The best way to build a base is from the back out.  This will maximize your space and keep buildings efficient.   The picture is to show you a basic outline of how I build my bases.  It does not contain any internal defense (such as anti-guild).  This is intentional because I just wanted you to see how I place my buildings.  Especially note how my refineries are placed.  This is the best way to place refineries.  They take up the least amount of space like this.  BUT CAUTION!  When you place refineries like that, they are extremely vulnerable to IX bombs blowing up in the center.  ONE TURRET will close the gap, preventing that from happening.  ALSO!  By placing refineries the way I do, you can place one turret only and protect all 3 refineries from enemy drones.  Put another turret on the other side and you are good to go!   Notice all that I was able to build because of efficient use of space.  And I still have plenty more space in there!

GOOD LUCK!

-Emprworm