Wow, I'm kinda surprised at all this. Well, I guess not really.
Some people I guess pick ONE way to play the game, and then keep playing that way forever.
I like to change it up. I never play the same game twice.
First time I played the game, I played it using a Custom race.
Then I slowly got better at the game, I think the first time I beat the game on a higher difficulty, I played through as the Terrans.
Then I got into the Yor, I think I played through a couple times.
Then recently I went back to Custom races, and went for a diplomacy win.
The latest game that I had was pretty cool. The game started out with me and the Drengens as being fairly close to each other. Being concerned about this I immediately started walling off my territory, so they ended up with their cluster of planets, plus a few planets here and there scattered throughout the galaxy. My intial plan involved allying myself with everyone EXCEPT the Drengens, because I wasn't an evil race, and I know there's no way they'd exist in my peaceful vision of the universe. They'd piss off SOMEONE.
So as empires grew, I was in 2nd place behind the Drengens. I started making small "donations" to them and trading to them early so as to not be sucked into an early war. I wanted plenty of time to research my diplomacy and get a monster economy going. I did have enough of a military going to be a deterent to anyone looking for an easy kill.
Surprise! Apparently nice guys finish last because the Drengen declared war on me anyways, even though my military was 2nd most powerful after them. I was somewhat surprised. In my experience the Drengens usually like to pick on the weakest militaries first. Our close borders must have made me a juicier target. However, my military wasn't prepared for an invasion. The Drengen came in, and took several worlds from me immediately. I hadn't researched Plantary Invasion or any soldiering techs.
The next few turns consisted of me milking my allies (who weren't allies yet, but everyone was "friendly") for technology and weapons. I got as much as I could though trading some of my less risky techs like engines for more miniaturization, better weapons, advanced hulls, etc. A few turns later I went into the Shipyard and designed my first medium vessel, to repel the Drengen.
The Drengen counterattack took time, but was very successful. My economy was too strong and although my ships were inferior at first, I overwhealmed them with numbers, and soon out-classed them in weapons technology. By the time I was re-conquering the planets the Drengen had taken from me, I had allied with 2 of the other 3 races in the game.
The Drengen were ultimately defeated. At this point my alliance win was in sight. However, I had one race left, and they wouldn't get any better than "friendly" They had too many things going against me to ever get "close" I think. Weren't my ethical alignment, and now that I'd beaten the Dregen, my influence was "Alarming".
I spent a few turns building influence starbases to flip their planets to me, and win peacefully, but that ticket them off and moved them from "friendly" to "warm". I did manage to flip a few planets though. Then however, I just decided to be a bad neighbor, and me and my 2 other allies beat them into submission. After losing 2 more planets and a buch of fleets to my highly advanced fleet, They surrendured to me. Good thing too! I was bankrupt. I re-designed the workhorse of my fleet with updated weapons, and armor to protect against Mass Drivers, since they were all equipped with ECM since the Drengen had focused on Missle tech. I made the mistake of upgrading ALL of my ships at once, which put me in the hole by 100,000 credits. Even though I was making almost 1000 credits a turn, I couldn't produce ANYTHING, nor would I be able to for quite awhile. But it all turned out well in the end.
Sorry - I didn't mean for this to be so huge!
But anyways, there's my story of my latest game, without relying on 70% population growth or anything like that.