I'll contribute my own little nuggets… I play obscene or suicidal, huge or gigantic maps (6-8 opponents -- all evil… I play as 'good'). I do customize my maps (custom home system with my cap planet a PQ 26, rest of system habitable with varying PQs… however -- I also play against only custom opponents -- so they get a just as good home system). I don't mess with Tech, Cultural, etc victories -- conquest only. I also set all planets, asteroids, and anomalies to abundant. Doubtless -- these tactics work to varying degrees depending on setup and style of play, but I can beat AI regularly at the highest levels.
1. Race setup.
I agree with morale and econ bonuses. I also like SOCIAL production and research. I play as Universalist - and bonuses small to mid so I can spread my bonuses out. I skip ALL military techs in initial techs -- only social/infrastructure techs. Can you tell I'm more of a "nester/builder"?
2. Early game
I buy my first colony ship on turn 1 -- plus my initial, this gives me 3 planets to start with. I also heavily recommend designing your own colony ships (I have two designs -- a fast colonizer with no range and a slower, more rangy colonizer… once you have a starbase or colony in a system -- range is henceforth pointless in that area). Remember to redesign regularly as you gain engine and miniaturization techs. I like to keep one colonizer close to home, giving me a second initial planet. The other -- I send further out. Colonize strategically -- focus on high PQs, systems with asteroids, and systems necessary to increase your range… However -- also be aware it's usually better to have 2 planets in a grid square than single planets in 2 grid squares.
Max out your production (100%) and set your taxes to a point where you have 55-60% morale… Another little trick -- on turn 1, set military allocation to 0 (since you 'bought' colonizer 1, no point in spending any turn 1 income on shipbuilding!).
BUILD, BUILD, BUILD -- I NEVER have a planet building nothing. For my cap planet -- it's usually 4-7 factories (depending on the existence of bonuses), followed by 2 morale buildings, followed by research buildings. On non-cap planets, I flip research and morale (since those planets start with such small populations, usually don't need morale). I also build on tile bonuses first, of course. Ideally -- I try for a solid 2-3-4 "mega industrial" planets (whether via tile bonus or asteroid bonus). These are going to be building my trade goods and wonders. Markets are pretty worthless early on (we're going to be falling into debt quite quickly). You're going to be losing money -- possibly quite a lot -- until you get better forms of government. That's OK -- just try to keep 4-5-6 turns of 'treasury' in reserve (i.e., enough so that you can research forms of government without needing to cut spending).
Tech-wise -- I skip the offensive and defensive trees almost entirely. The AI will research 'em for me, so why bother? I first path to Diplo translators, then RepairBots (Enhanced Miniaturization), then Restaurant of Eternity (Trade), then Advanced Hulls, then Aphrodisiac (Habitat Improvement)… Depending on my map - I MIGHT deviate into Extreme colonization and the specialized colonization techs but only if there's a clear choice (i.e., I have multiple high PQ Barren Worlds in my vicinity, etc. If it's a mixed bag, forget it. I'll let the AI colonize and culturally flip 'em later). Immediately begin building trade goods and galactic wonders as soon as they are available.
DO research sensors early and get some survey ships up and running. I normally have 6-8 survey ships scouring the galaxy, FAR outpacing the AI. I've even built my custom opponents to START with sensors 1 -- and they still refuse to build survey ships. The bonuses are small -- but find 5 +1 soldiering, 3 or 4 +1 econ, eventually -- they add up. You also DESPERATELY need the $$$ anomalies.
Once I've built Diplomatic Translators -- I go on my first trading splurge. ALWAYS start with the minors -- especially early, you can get all the baseline offensive techs from them. DO ask for cash -- and get them to sign research treaties (econ treaties are usually a little overly expensive). DON'T trade them any techs that lead to galactic wonders or trade goods (super achievements -- the "one per race" are OK however. In fact, since you'll inevitably be conquering them, you WANT them to build econ capitals, tech capitals, etc). There is virtually no downside to teching up minors.... the better their planets (more advanced buildings), the better they are when you conquer them. Minors are also an EXCELLENT source of cash in the early to mid game in order to keep your treasury full. I'll glady trade them almost my entire tech advantage to get all their cash. They'll just waste it on AI extortion anyway

Then, run through the majors. DON'T expect to get "even up" trades and DO be uniform in your offers across all races (i.e., if I trade Basic Miniaturization to one race, I'll usually trade it to all). By even up - I mean that you may find yourself dealing 2-3-4-5 techs for 1. Don’t' worry about it. Don't think of it as 1 vs. 1 -- it's you vs. everyone else. This means if it takes 4 techs to get 1, but you trade the same 4 techs to 7 different races, acquiring 1 new tech from each -- you actually come out AHEAD (7 new techs for 4). There are times (later in the game... not so much early) where I will trade 10-12 techs just to get 1 in return.
As far as starbases - you usually have a bit of time before anyone attacks you. So DON'T focus on building up starbases. DO focus on capturing as many resources as possible. In other words - better to have that contructor on its way to an unclaimed resource than it is building onto an existing resource starbase.
3. MID-game.
By this point - I'm usually getting close to being debt or needing to radically lower my production. Make a beeline for the governmental techs (Republic, Democracy, Federation). Republic usually isn't enough -- Democracy should keep you financially viable. Depending on how lucky you got with anomalies and meeting minors (to trade techs for cash) - you might need to do this earlier.
Hit the next level of trade goods and Galactic wonders… Master Trade, Terraforming, Ultra Spices, Grav accelerators, etc.
Keep trading like mad. Start with the minors -- once you get the Galactic Showcase, you should be able to now start getting econ treaties from the minors, and possibly start acquiring research treaties from the majors. Again… let yourself get 'taken' in trades if necessary.
Start trade routes with possible enemies (close AI races, AI races that start to slide past wary into hostile). Preemptive diplomatic wars aren't a bad idea either --- even when an AI race has nothing to trade, I'll give him a few techs to DoW on another AI who appears to be sizing me up for invasion. Play powerful enemies against each other… keep enemies busy with someone besides yourself. I also don't hesitate to give up cash (if I can afford it) in order to buy peace… Sure - I'm simpering coward now… Just wait!
If someone DoWs on you -- DON'T panic. Immediately get ALL other AIs to turn on him. Sacrifice as many techs as necessary. By this point, I usually have not built even my first offensive ship -- I stay alive through diplomacy. The Go'Auld, Ori, or Wraith (some of my custom evil races) might be able to mop the floor and easily seize my undefended planets… but they find it awfully hard to do when there's a whole gauntlet of enemies between me and them! It's not unusual for every other race in my game to be at war with everyone else (but not me) -- while I'm happily building my planets, starbases, and slowly becoming an unstoppable economic, research, and industrial powerhouse.
4. End Game
I don't build ANY ships until I've all but tech'ed out. There are exceptions - if I can't use diplomatic tricks to keep enemies at bay, I'll go early. This keeps my treasury in good shape and let's me focus on planet enhancements, anomaly research, and starbases. By this point -- I'm usually at 80% taxes, but still maintaining a morale in the 70-80% range. I'm also hauling in 2-3K in income and no tech is taking longer than 6 turns to research. Add my other bonuses (from anomalies and trade goods) -- and conquering everyone is pretty much a foregone conclusion.