i like the second energy orb image. If you get a cloud image as a background, add some sea, shadows, will look more whole and realistic
If you want some tips on material effects, such as bumpmaps, transmap, ambientmap, just ask away ... I have a few tricks of the trade
Ive attched two images. One of a tester model i did ... Took me a day to model. Its just a 3d sketch basically. Barely no light effects, texture effects, etc ... I then did a similiar render using a developing final model set. You can see the difference - realistic textures, etc. Check out cgtextures.com ...
Also, check outhttp://www.anim8or.com/smf/index.php?topic=435.0
its a topic i started about a month ago regarding a myst style game im designing, but it has a lot of advice given to me from fellow anim8ors in regards to textures, etc
Also has a way of creating leaves! which might b useful for your tree