[Shadow99]

A tactic that helped me a few times with enemies starting in the same system (especially when they were larger) was to mine around my planet (aka on top of it). I still lost a few planets, but I was able to build up resources in other locations while keeping most of my planets safe this way. It's ineffiecent when the enemy isn't in your system though.

Stations/bases on warp points is also a fav of mine. Nothing like a couple simple space yards & a massive defense base (loaded to the hilt with guns & shields) to keep any enemy vessels from making it through mined warp points...