You are limited only by your imagination, your coil and wick installation skills, and yeah, the size of the chamber, don't go putting a 10 mm coil in there, it's not gonna fit.
Also, sometimes it can be good to watch (some) reviewers build and wick your new tank. it can (in some cases) be useful as far as just building and wicking it generally.
Otherwise, play around to your heart's content although I will say (even though I'm playing around a bit t the moment with more exotic coils, for fun) they are not necessarily better than a simple round wire build. Etc.
Good luck,
Anna