There's a lot of ways to pull an item together ...
The Asari: I would look for the Mad Scientist's hair, and a few thin rolls of the 'green stuff'. Using the hair piece would give you the 'connection' you'll need and the beginning base to add any extra 'tenacles' you think she needs:
I can't get the pic to work ...http://www.bricklink.com/catalogItemPic.asp?S=col04-16
Be sure to share!!
And welcome to the BF forum :o)
Edit: I'll be right back. I'll grab a couple of pics showing you what I mean with the 'green stuff'.
Edit:edit: Here is a project I've been working with using the green stuff only (following Hawkx advice with the foil - which I why I'd recommend a hair piece)
Sorry for the poor pic quality, but you get the idea. I rolled the 'green stuff' into very small rounds for this. The idea should work perfect with the Mad Scientist's hair (may for the Turian too).