Winning the landgrab

I always send them to the stars closest to me and just keep going outwards, having the survey vessel go around looking at the star systems helps too.

1) Instead of trying to find the planets, I make the planets come to me. No, seriously - when I start a new game, I set stars, planets, and habitable planets all to Abundant. With these settings, almost every single star will have habitable planets, and most of those will have at least one good habitable planet.

I don't even bother with scouting. The flagship goes on a permanent survey mission until the anomalies are gone. Every time I crank out a colony ship, I just send it either blind to a new star system or to a planet I've already spotted.

2) I used to build colony ships normally and buy the first factory on each planet. That quit working at the higher difficulty levels. Now, playing at Crippling, I've found that the best thing to do is set my Military and Research sliders to 40% each, leaving the Social slider locked at 20%.

Then, depending on how much cash I have coming in, I purchase transports. Usually, I let a new transport spend a couple of turns in production, then buy the remainder, so I'm pumping out transports every three turns on my home planet. On the buy turn, I set the Military slider to zero, jumping research to 80% for those turns, then set it back to 40% to start the next transport going.

I also set my first few colonies to building transports in bigger galaxies, but I only buy and reset production based on my home planet. That one planet is more than enough micromanagement for me - I'm sure there are ways to improve on this with enough time and patience.   

I've seen the computers strategy at the beginning of the game. They bankrupt themselves by putting their spending rate to 100% and start buying colony ships until they can't anymore then start building. They also build a starport first instead of a factory to get a head start.

Actually, it shouldn't kill you if you don't do as well. You just need a few select planets, a foundry world, for creating ships, a cash cow, and research center. With these you can begin to expand and conquer. Small empires don't always stay small.

That said, remember you're small, don't go annoying the big boys untill you can handle it.

don't be afraid to send your colony ships out to do their own scouting. many ppl don't even bother scouting with their flagship. they just set it to automatically fetch anomolies and forget about it. also note that your map size influences your colony rush strategy. on the small maps it can make sense to rush buy ships. on the larger ones it that will get you smoked real quick. larger maps think longterm. maybe buy a factory or starport here and there, but don't buy ships unless you just have to grab a great planet right out from under an opponent that is right on top of it. remember, that money has to last you until your planets grow enough to start producing money. if you rush out ships and break yourself you can find yourself with you spending slider down at 30% for a long time, giving opponents plenty of chance to out tech you, build up a military, and generally buy yourself a long hard slog or a defeat.

working the kinks out of your rush strategy will take some time, be patient. i used to think mine was just fine but now it is about 4x as effective as it was. i no longer have to ever turn down my spending slider and i still overrun the map. my current game(only set to tough) i got 2/3 of the planets(medium map) against 3 opponents without any money worries, and even started producing warships first. i am not saying i am great, just that i have a highly refined rush strategy, developed over time. if you just can't wait tho let us know what map size and difficulty lvl you are playing on and someone is certain to supply you some specific tips.

oh, one non specific tip. population growth is critical to maintaining a rush. not only to fill ships, but to get your economy running.

also concider researching impulse drive immediatly. it can more or less double the speed of the colony ships you produce.

Map size is key, as is planet/star abundance. I agree with most of the posters above. For me i play abundant everything except anomolies, so scouting is not needed. For me :

1) Get pop growth bonuses and production bonuses.
2) get impulse drive fast, and only generally buy 1-2 colony ships outright
3) get sensors fast and get 2-3 more survey ships going
4) get 1-2 other production worlds set up. (quick build a factory or two)
5) get colony ships rolling off with around 40% to military.
6) try to grab up best planets farthest away, scouting on the way, colonize inner last.
7) i like to focus planets without shipyard to social, and build the shipyard last. (about 5-6 deep into the queue).

This gives you a leg up on getting your economy going later, since these planets will get built up and the population will grow without getting depleted. Once the yard is built i remove the focus and generally start building constructors on these low production planets for the resource grab phase...