Some of the fun parts about the strategy of the game is trying to get some of the achievements. For example, I was going for the no military research and all civic research badge. This was going to cause a lot of problems. Why? Well there would be no flak frigates, no seige frigates, and of course, no LRM's. How do I solve my problems? Easy, I had to build all Capital ships. My next problem was the pace they were built. I was taking damage because the AI could ping me at anytime with frigates and such. With long production times and limited resources, it was hard to keep up. I was on the defensive for most of the beginning of the game. Finally, when I had enough cap ships, I could use them to colonize, defend, and attack other worlds. While I was at it during the game, I was also able to get the diversification badge and maximum cap ship badge. There are many strategies in the game, you just have to look at the bigger picture. Not just the combat aspect.

Also, consider this strategy:

You see the A/I building a lot of flak frigates. Would you send in a bunch of carriers to destroy the frigates? Of course not. You would go heavy on the LRMs and hold back your fighters until all the flak was taken care of. It is entirely possible you have the stronger fleet (by the numbers), but if you mismatch your forces you can still be torn to pieces.

Or maybe this strategy:

Setting up choke points. Sure it is great to have defenses on all your worlds. That just takes too much time to build up. What you need is two strong defensive worlds at each end of your territory. I find myself selling and rebuilding my frigate factories near the edge of my territory. I want to get my fresh frigates back into the fight without having to go from planet to planet to planet before they show up to the fight. There is no reason to build up the defenses on your central worlds if nobody can get to them.