I've seen this done in multiple ways but here is my approach to the Star Trek Original Series Female Romulan Commander

Base Figure: Playmates Star Trek Torres as Klingon, Hand Sculpted Sleeve Cuff (with Milliput)...I was a bit lazy and only did one sleeve.
Head: Playmates Sea-Quest Hitchcock, Hand Sculpted Ears, added a bit of eye shadow, eyeliner and "Romulan" eyebrows.
Lower Legs: Playmates Star Trek Kes, with Hand Sculpted Boots...really only the upper portion above the knee...to give the thigh high boot effect without having to completely sculpting an entire boot.
Scarf: Metallic ribbon from a fabric store, painted, with a wire running up the back to allow it to keep shape

I am a hack and masher of parts more so than anything else so do my best to hide my sculpting and keep it minimal.