Hello! I am (Spy)z0rs, leader of clan Spy (with (Spy)Incognito)!
The strategies contained will hopefully help you!
Nexus6...
The default base location, I believe, is the best for aliens. Many would disagree, with the jetpacks and all, but I don't.
Best defensive item on this map: trappers
Postioning:
Firstly, when s2, OM immediately gets moved to the top LEFT space, and an egg in the top right.
2. An egg/booster combo under the OM position
3. Ok, here is the fun bit! Across from the 'top' egg, there is a spot back in the base where humans can sit and shoot your egg. Place an egg in the alcove next to here, and a trapper down low, facing away from the wall (on the wall)
4. Do the same on the oppisite wall, but no egg, just trapper.
5. Trap the non-pipe door, by putting a trapper along the left side (if facing it) and one along the right.
6. On the pipe-door, place a trapper on the right, outside the inner wall, on the curved wall... if you get what I mean...
7. With the last of your BP, place an egg above pipe-door, up above the slanted crossbar, over to the right as far as you can!
Conclusion for Nexus6: With a dretch or two, any onslought is easily stopped.
Pics and more maps coming!