I'd like to preface my following answers with the fact that they are how I would play one of my personal games IF I were planning a Space win. I am not very good at milking a game and have never really paid attention to score until playing in the SGOTM (and we received the wooden spoon there).
Long term goals if this were my personal game. I will break my goals down to specific units, towns and builds.
Overall plan: No more wars, get our Empire to max out on gold potential, build specific wonders to help with gold, beeline to space with no stopping at un-needed techs. For me at this point of the game it's all about the bling. More cash means more research means quicker tech means getting out of the solar system quicker.
1.) Workers: After finishing off the Persians set-up worker groups to maximize my existing cities and make sure that every citizen has a workable tile (this would occupy my workers up to the time of steam). Cities that are in the first two rings of both the Palace and Forbiden Palace would get a mixture of shield improvement and food improvements. The outer cities concentrate more on food improvements to get the cities as large as possible. (AlanH makes us repete the mantra "Food = Power" before every turn set in Jump Masters)
I would set up two to three towns that have high food potential and small shield potential to become worker pumps. These cities would be used to create workers to join into the cities in our two cores (thanks to Northern Pike for this technique, SGOTM2 Team Scout) With this technique cities around the forbidden palace and the palace can be raised to their full population potential quite quickly.
When steam comes group workers to first make a transit network from one side of the island to the other(both north and south and east to west) concentrating on unit movement, incase we do get attacked units can be moved quickly to the problem areas. Once that is completed work on getting all worked tiles in my two cores railed first, then working outward to the more distant towns.
Once the rail network is completed a small group 15-20 workers will be kept to play "whack-a-mole" when polution pops up it's ugly head. The rest of the workers either get added to cities after Hospitals are built to increase population, or get disbanded to save gpt on upkeep.
2.) Military:Once Persia is gone I would disband most of our swords and any warriors left hanging around and only keep a force of fast units around big enough to keep the other island from getting any ideas about a naval invasion. This of course only comes after getting to republic (no more need for MP). Outer ring cities will build arti that can be scattered around our land mass to hit any ships that may have ideas about invading us. Spears get upgraded to the most current defensive unit available as do the fast units. Once in the late industrail age build nothing but tanks and upgrade them to MA. (I love MA) I have never found a need to build much of a Navy at this point or an Air Force. I normally build a few just because I like the looks of them.
City Improvements:
First ring cities: will get most all improvements available. Granary - Marketplace - Lib - Aqueduct (if needed) - Bank - Universities - Hospitals - Factory. I will also do courthouses if it has more than one wasted shield and mass transit if I'm having a problem with the cities polution.
Outer cities: Courthouse - Marketplace - Lib - Uni - Aqueduct - Hospital - Police station if it will make a difference in corruption. These get done much slower but I will occasionally rush some of these if it will improve the gold output of that city.
Techs:
Middle Ages:
I beeline to Gun powder (great trade bait) first and then take the high road to Democracy and then try to be first to Theory of Gravity
Industrial Age:
Beeline to Electronics. I do not pick up any non-requisite techs in the modern era. I let the opposition do this for me. Once I get towards the end of the modern era I stop selling techs to the other civ's (unless I am gettig short on cash for research)
Modern Age:
Fission (to build the UN) Rockerty - Space fight, and then the rest of the needed techs to build the Alpha-centuri-mobile
By the middle of the Industrial Age I am normally turning all of the techs in 4 turn and rarely or never getting beat to a tech.
Wonders:
Smith's - Hoover - ToE - UN are the ones I will try the hardest to get
Leo's - Copernicus' - Bach - Newton's - Seti are nice but normally not a must to win
Small Wonders:
Wall Street - Inteligence Agency - Iron Works (ooh I love when I can build that one - 150 shield per turn city
)
I have won 4 or 5 space races on Monarch and this was my plan of attack. I have been wanting to move up to Emperor to see if it will still work there but I don't have time because of SG's. Look this over and give me your opinion on what I'm doing right or wrong.
Sorry I could not go into more detail with city names and the such but I don't have the game infront of me right now. I'm flying over Colorado and typing this on my lap top. I'll send it to you guys when I land.
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Mistfit
Edit: I thought the quote was "The Devil is in the Details" 
s Good answers, as far as they go. But remember, God is in the details.
In COTM1 I neglected my navy, and didn't get the other continent dealt with until the 1400s or so. The early conquest is a phase of the game I'm still working on. 
Death to Hellboy! I can send you a hand-drawn evil jester my friend did years ago if you want.
I'm sure there is a lurker out there who can give us an answer.
