Halloween Girls

Here were the girls costumes.
I tried to get incorporate snakes but it was not as good.

i think you need to light the background and the second shot looks over exposed. I'm no pro but thats what i see...

I think lighting is flat and over-exposed. Subjects are too close to the background.

The composition in #2 and #3 have much to be desired.

#2 she looks half asleep, a cut off hand, and you've fit in awkwardly in there cutting off her legs too. The plastic bra strap looks bad too. Flash is too much and/or too harsh. Her head position/tilt doesn't seem to work here.
#3 well your backdrop isn't big enough for 2 people obviously since you can see both edges. And your lighting is too strong and too direct.

All 3 photos need to be developed more as they look rather like out-of-camera JPGs or RAW conversions using default parameters or a basic converter such as photoshop elements. Tone curve adjustment will do a lot better.