Without specifics (ie, how much you can spend on each basket and who they're being auctioned off to etc.) these are some of my elaborate ideas!
Girls Night Out Basket:
Containing some free drink cards to favorite local bars.
A free taxi cab ride home card
A disposable camera for pictures
Some mints and gum for fresh breath
And a few gift certificates to taco bell (for after the night of drinking

)
Perhaps the items could be placed in tissue paper inside an inexpensive look-alike Kate Spade Purse too
Wizzard of Oz Basket:
Containing a donation of ruby earring, pendant or ring. (Dorothy)
A cute stuffed beanie-baby dog that looks like Toto.
Free movie passes (Oz)
Something heart related: like a key chain, a pen, stationary (the Lion)
A dictionary (The Scarecrow)
Obvious packaging in a picnick basket.
Hawaii Chi-O Basket:
Containing a month's worth of tanning at the local salon.
Some tanning goggles.
Tanning lotion.
A pair of nice sun glasses
Cheap margarita classes and a few umbrellas (for the drinks)
And a bunch of lays as the filler
Perhaps the items could be placed into a nice beach bag, or one of those sun hats?
If I think of more I'll let ya know!