Feel free to message me with any questions, I love playing domination victories
The main thing to note in domination victories is the era where your UU is the strongest. I'll use the Mongols as an example since they're my favorite civ to play with (and the keshiks are hands down the best unit in the game).
- Always perform trades with the AI. If you have luxury resources, you should be selling it to them for as much gold as you can get (240 for standard, 200 for quick)
- In the beginning of the game, focus on going tall. Lock in the tiles with the best resources (with preferences set to production, to gain that extra hammer when growing)
- Buy a worker as soon as you can. This includes trading gpt for lump sum to AIs so you can get that worker and start improving tiles
- Steal workers if necessary (Only do this once- any more and the city states will hate you)
- I usually open up with Liberty, I find the free settler and worker + GP is very strong, and someone like a GS might just be all you need to bulb into chivalry to get your keshiks
- Manage your cities wisely. You only need 1 hardcore production city that'll pump out military units. Save the cost of barracks/armory for your other cities and let them focus on gold or GP generation
- Rush NC. In prince you should be able to rush a GL as well quite easily, so do that to get the philosophy as well into the NC. In the meantime, you should have enough techs researched that will allow your workers to finish improving the tiles around your cities while you're waiting
- Build build build your units' predecessors. In this case it would be horse archers. As soon as you tech up to chivalry, you should have at least 4-5 ready to upgrade and ready to raze the land. You don't want to lose any speed at all when you're at your strongest
- Faith is not that important. It's nice to get a pantheon and maybe some beliefs, but it's not necessary. Don't overcommit to building faith over your precious horse archers- you are going for a domination victory after all
So those were some basic ways to micromanage your civ before you begin the war. So, now that war has erupted, what do you do?
- Get familiar with the combat system, in particular, zone of control. An enemy unit will use up all their movement points if they walk adjacent to you. Use this to your advantage to keep high-value units safe.
- Get familiar with the combat system regarding ranged units. Keshiks can shoot in a radius of 2 unless their vision is blocked by rough terrain. On the other hand, placing a keshik on a hill will grant it 2 range regardless of terrain (except mountains of course)
- Keshiks are extremely easy to micro. Use them to walk in range, attack, and walk back out. It's virtually impossible for them to get hurt. That being said, play cautiously, so they won't get hurt. If it means sacrificing an attack because you may be hurt the next turn, so be it and move into a better position.
- A team of 4-5 Keshiks can easily take down a city without getting hurt either. Simply move them to the borders of a city (2+ tiles away), move then in, attack, and move them back out of range. You won't get hurt and it's ridiculously broken
- When conquering, make sure to build 1 horseman as well. Keshiks can't conquer, so you need a quick melee unit that can sweep up the remains of a city. The horsemen are convenient, 5 movement troops, perfect in that regard.
- Always go 3 deep into the shock/drill promotions, and their ranged equivalents. Double attack (unlocked after accuracy/barrage III) is too good. You will essentially gain xp at double the rate with double attack, not to mention Quick Study(Keshik Unique ability +50%xp). The only other alternative is March(unlocked after accuracy/barrage II), but since keshiks won't be getting hurt, don't bother with that.
- Assuming you've done all that and are just about to conquer a civ, they will have that "last resort" peace treaty, which is usually all of their money and resources just to have peace. Take that offer, use the temporary 10 turns to regroup/ make an even larger army in preparation to take over the world. After the peace is done, you may choose to eliminate them as you see fit.
- Always raze cities or find a way to get rid of them (trade them away). You don't need them and the unhappiness isn't worth it. The only reason I would keep them would be if they are in range of a luxury resource (to pay for the unhappiness they are generating), and even then, I would raze them until they have 1 Pop and then puppet them to minimize unhappiness.
- Never conquer city states, it'll generate too much unhappiness which gets annoying because you can't raze them since they are capitols
Hope that helps! Let me know how you do