Set up an Immense galaxy, with abundant stars, planets, resources, anomalies, etc. Starting races start Very Far apart. (Allows everyone to build up their base of operations before being forced to deal with nosy neighbors.) Usually 7 or more major races, with 8 minor races.
I always play a custom race. That way I can pile on the Research advantages: Creative, Research +20%, +10% on planet quality, + Morale, Technologist Party in control. Starting tech focuses on ship propulsion systems, research, and production strength. Set race to Adaptive as trait and Hive for Super Ability. The combination gives you more planets to colonize (Toxic and Aquatic) and makes your people more productive.
Start: Set tax to a level where Morale drops to 52%. (The people are slightly more happy than unhappy.) Set production to 100%. Split production to 20% military/20% social/60% research. Set Espionage to where a Spy is produced in 10 turns. (An expensive pain, but necessary in the long run. You _will_ need a stockpile of Spies eventually.)
This arrangement _should_ generate a small Treasury increase to begin. By Turn 20, though...
Set the Miner on Automatic. Aim the Colony ship with an eye towards going as far away as possible. This is because its hardware lets it go further away from your controlled planets than anything that you are likely to be able to build for quite a long while. It seems a waste to expend it on a nearby planet. The Flagship should be unmasking planets and making a serious effort to hit any non-wormhole anomaly that gets spotted. (The occasional bc windfall will help the Treasury immensely. You want to stay solvent as long as possible without reducing production.)
Do NOT settle any planet below a quality of 10. Having that +10% planet quality racial trait translates into a +1 world quality, minimum. (Your homeworld will be an 11 while everyone else starts with a 10.) A 9 quality planet becomes 9.9, and rounds _down_, so you get no benefit. And the higher the planet quality, the more buildable squares you'll have available. Note that even being adaptive, settling a Toxic or Aquatic planet will give you more squares, but your planet productivity **sucks**.
For Research, start hammering on propulsion systems, with sojourns into Trade, Diplomacy, Research, and Productivity. The propulsion gets your ships to other and more planets faster. And you _will_ want to colonize other planets ASAP because each one automatically feeds your Research 7-12 points, _immediately_. When you can research something mundane like Sensors or Stellar Cartography within 2 or 3 weeks, do so.
Build Colony ships ASAP. When you finish researching faster engines, design a faster Colony ship, and skip the sensors, weapons, etc. You want the fastest Colony module available, so use a Cargo hull, add the Colony module, and pile on the engines. If you have 5 points left over after engines, add Life Support. Ships will spend more time in construction, but they'll make up the difference during travel. Build Survey ships later when you have excess production available, or a LOT of nearby anomalies to gather.
Run this pattern until your Treasury is about to go into the read. By then you should have an impressive library of techs already researched, and your Trade/Diplomacy value should be respectable. Go to the Diplomacy screen. Contact one of the other races. Check your list of techs that you have that they don't. Excluding Trade, Diplomacy, Production, Propulsion, Research, and Weapons, see what you have that is at least two levels beyond what the alien has. Choose one or two such techs. Then offer to sell those for cash. (Do NOT succumb to the temptation of trading several techs for one of his! It will cost you less to research it yourself.) You _should_ have a negotiating advantage, so each such tech offered should yield several hundred to a couple thousand bc's. Transaction completed move on to ALL of the other available races, offering only the same techs you just sold. (Better you should get the profit than the opponent that would turn around and sell it on instead.) If another race is short on cash, make up the difference in Influence.
Aside from all of this, resist the urge to waste time and money building warships. Wait until you actually need them. If you do, switch to 100% military production until you have enough ships to meet the crisis. Just remember that anything you build will very quickly become obsolete.
I find that this strategy works quite well for me.
