I haven't had time to utilize every policy and play through every civ yet, but I've been starting to notice some patterns with the way I play, for better or worse. With that in mind, I try playing a little differently in subsequent games, but I won't deny that I have certain preferences that I push for. Some policies are great contextually, others are often good for the whole game, whether in peace or war. With the exception of Survey, I'm not sure if there are policies which are just outright horrible.
That said, in no specific order...
1. Conscription (State Workforce) / Levee En Masse (Mobilization)
This series of policies are way too important to me lol. I don't necessarily leave Conscription in my gov't for the rest of the game; sometimes it's only saving me 3 gold at best if my army hasn't grown a lot. But in early game this could potentially make my entire army free of maintenance. Levee En Masse is available in the Modern era, at which point units start costing about 6 gpt, but I think it's still a very fine policy to have.
2. Ilkum (Craftmanship) / Serfdom (Feudalism) / Public Works (Civil Engineering)
This series of policies are also nice to have. But unlike Conscription / Levee En Masse, I'm usually rotating these policies in and out of my gov't pretty often. At least with Ilkum, I get the chance to squeeze in a Builder between things in my build queues without feeling like I fall too far behind on whatever. But eventually I've plopped down as many improvements as I would've liked, with some remaining spaces left for districts and wonders in the very near future, and I stop building Builders for quite awhile. This series is more useful late game than early game, at which point I've probably expanded and captured quite a bit.
3. Their Finest Hour (Suffrage) / Strategic Air Force (Globalization)
I'm silly and I like air units too much.
4. Caravansaries (Foreign Trade) / Triangular Trade (Mercantilism)
These bonuses are simple, but they apply to internal and external trade routes, so I'm usually very happy to use this series of policies. I can't quite justify using Caravansaries early game, particularly if I only have one or two trade routes going, but eventually once I have ~5 active trade routes or more? A bonus +10 gold or +20 gold per turn is pretty awesome to have and covers maintenance quite well.
5. Logistics (Mercantilism)
Holy crap this policy is pretty awesome. As most folks have pointed out, the move bonus applies for non-military units as well, so Builders which are usually in home territory all the time will always be moving faster. But even for its intended purpose (or what I think is its intended purpose), Logistics is a fine policy for maintaining momentum in capturing cities. This helps a lot with shuffling ranged units around as well, particularly if roads are involved. Once I get this policy, I tend to keep it in my gov't for the rest of the game.
6. New Deal (Suffrage)
The bonuses provided by this policy are insane. +4 housing and +2 amenities is a very worthwhile trade for 8 gold imo. And by that time, one should be making enough money to cover these costs and more anyway, particularly if one has Triangular Trade running.
7. Maritime Industries (Foreign Trade) / Press Gangs (Colonialism) / International Waters (Cold War)
I'm silly and I like naval units too much, though admittedly I like air units more.
8. Charismatic Leader (Political Philosophy) / Gunboat Diplomacy (Totalitarianism)
I've honestly never got Diplomatic League to do anything noticeable for me, so I might as well only have 1 diplomatic policy for the longest time. With that said, gaining more influence points is always a big plus for me. City state bonuses are actually really nice to have, and I also like being suzerain of a city state if it's sitting between me and another civ.
9. Professional Army (Mercenaries)
I like this policy in practice, but I think it's terrible for me to be leaving it in my gov't for too long. Ideally, I think I should only swap in Professional Army when I reach the right technology, mass upgrade my units, then swap it out immediately once I'm satisfied with my army. In practice, it may take multiple turns for me to upgrade my army thoroughly, especially if my army has diverse and requires many different techs for upgrading. Eventually, I tend to forget and leave Professional Army in for the rest of the game.
One thing I've found very strange is that there's no policy for +4 Great Engineer points per turn. The most one will ever get is +2 per turn from Invention (Humanism). Absent of Great Prophets, I think every other great person has a +4 policy. I actually don't use the wildcard slots for generating great people points all the time either.
Bonus points to you if you can figure out what my ideal gov't looks like (no bonus slots).
That said, in no specific order...
1. Conscription (State Workforce) / Levee En Masse (Mobilization)
This series of policies are way too important to me lol. I don't necessarily leave Conscription in my gov't for the rest of the game; sometimes it's only saving me 3 gold at best if my army hasn't grown a lot. But in early game this could potentially make my entire army free of maintenance. Levee En Masse is available in the Modern era, at which point units start costing about 6 gpt, but I think it's still a very fine policy to have.
2. Ilkum (Craftmanship) / Serfdom (Feudalism) / Public Works (Civil Engineering)
This series of policies are also nice to have. But unlike Conscription / Levee En Masse, I'm usually rotating these policies in and out of my gov't pretty often. At least with Ilkum, I get the chance to squeeze in a Builder between things in my build queues without feeling like I fall too far behind on whatever. But eventually I've plopped down as many improvements as I would've liked, with some remaining spaces left for districts and wonders in the very near future, and I stop building Builders for quite awhile. This series is more useful late game than early game, at which point I've probably expanded and captured quite a bit.
3. Their Finest Hour (Suffrage) / Strategic Air Force (Globalization)
I'm silly and I like air units too much.
4. Caravansaries (Foreign Trade) / Triangular Trade (Mercantilism)
These bonuses are simple, but they apply to internal and external trade routes, so I'm usually very happy to use this series of policies. I can't quite justify using Caravansaries early game, particularly if I only have one or two trade routes going, but eventually once I have ~5 active trade routes or more? A bonus +10 gold or +20 gold per turn is pretty awesome to have and covers maintenance quite well.
5. Logistics (Mercantilism)
Holy crap this policy is pretty awesome. As most folks have pointed out, the move bonus applies for non-military units as well, so Builders which are usually in home territory all the time will always be moving faster. But even for its intended purpose (or what I think is its intended purpose), Logistics is a fine policy for maintaining momentum in capturing cities. This helps a lot with shuffling ranged units around as well, particularly if roads are involved. Once I get this policy, I tend to keep it in my gov't for the rest of the game.
6. New Deal (Suffrage)
The bonuses provided by this policy are insane. +4 housing and +2 amenities is a very worthwhile trade for 8 gold imo. And by that time, one should be making enough money to cover these costs and more anyway, particularly if one has Triangular Trade running.
7. Maritime Industries (Foreign Trade) / Press Gangs (Colonialism) / International Waters (Cold War)
I'm silly and I like naval units too much, though admittedly I like air units more.
8. Charismatic Leader (Political Philosophy) / Gunboat Diplomacy (Totalitarianism)
I've honestly never got Diplomatic League to do anything noticeable for me, so I might as well only have 1 diplomatic policy for the longest time. With that said, gaining more influence points is always a big plus for me. City state bonuses are actually really nice to have, and I also like being suzerain of a city state if it's sitting between me and another civ.
9. Professional Army (Mercenaries)
I like this policy in practice, but I think it's terrible for me to be leaving it in my gov't for too long. Ideally, I think I should only swap in Professional Army when I reach the right technology, mass upgrade my units, then swap it out immediately once I'm satisfied with my army. In practice, it may take multiple turns for me to upgrade my army thoroughly, especially if my army has diverse and requires many different techs for upgrading. Eventually, I tend to forget and leave Professional Army in for the rest of the game.
One thing I've found very strange is that there's no policy for +4 Great Engineer points per turn. The most one will ever get is +2 per turn from Invention (Humanism). Absent of Great Prophets, I think every other great person has a +4 policy. I actually don't use the wildcard slots for generating great people points all the time either.
Bonus points to you if you can figure out what my ideal gov't looks like (no bonus slots).
). Say you build some workers and plop out a couple improvements. It may pay to pop out an extra worker and pre chop/harvest the spots for your districts as well. rather than building a non boosted builder later or waste the harvest yield. Say you mark out your districts but the optimum tiles are 2nd or 3rd ring. It may pay to save up your gold for a bit and buy all the tiles you need at once with Surveying rather than paying full price as you go. 
