Just a couple more shots of my progress in sculpting.
I've started getting familiar with the material presets and effects, and have been able to add different attributes such as specularity onto my models, giving them that shiny, glossy look.
After generally experimenting and creating the bottom two faces, I watched a couple of tutorials and decided to try something more realistic, resulting in the third sculpt. I'm still not great at colouring using this software, but I think I'm becoming more able to sculpt more realistic forms. It's clear that in comparison my previous models were very flat (and not just because they're aliens).
I'm still not 100% on my alien's actual appearance yet - I've been working on concept art which I'll upload soon.
p.s. thanks for the kind comments on the last post :)