Gardener Basket-put in gardening gloves, the small gardening tools, seeds, a small watering can, a package of Miracle Grow, a cute flowerpot, a cute garden hat or visor, those little stakes you put in the ground to mark what plants are where.
All-American Basket-find red, white and blue stuff or stars and stripes stuff. This is a nice one because you are sort of doing it around a color, so everything doesn't have to match a theme as much as the color....you can do red paper plates, white napkins, blue plastic silverware, a red candle, some red & white or blue & white or red, white & blue striped tea towels, some little cute thing (maybe a candle holder) with stars on it...as long as the thing fits the color scheme/ stars & stripes theme or even an "Americana" theme, you can put it in there.
Patio Basket-probably a good one to do now because this stuff is all on sale...nicer plastic (not throwaway) plates, cups, plastic wineglasses, those wineglass rings to mark people's wineglasses, some summery napkins, a jar of summer salsa and a bag of chips. If you can find a summery plastic platter, put it all on that instead of in a basket..or put it in a plastic ice bucket that can be used on the patio.
Autumn Basket-pick things with autumn colors/designs...I did one of these for a fundraiser last year and got everything at the Christmas tree Shop...it had mulling spices for cider, little paper plates with leaves on them, a small loaf pan with pumpkins on it, a Harvest scented candle, 2 coffee mugs with autumn leaves on them, a bag of fancy cookies. If you have a farm in your area that does hayrides maybe a gift certificate for that.
Hot Chocolate Basket-Fancy hot chocolate, cookies, mugs, little plates, peppermint sticks for stirrers.
Christmas Basket-you could do a variety of Christmas stuff or pick a specific "Christmasy" thing and do everything in that (like candy canes, reindeers, gingerbread people, Santas). Or do a "gold ornament basket" or a "red and green" basket. Ornament baskets are neat because you hang a couple of the ornaments off the basket handle so they dangle inside...that's very eye-catching.
Hanukah Basket-fill it with Hanukah-themed items.
Halloween Basket-if the auction will take place before Halloween. If not make it a Thanksgiving or Christmas basket.
Winter Basket-if you want to be really "PC" and not technically do Christmas, then do a winter theme with snowmen and snowflake themed stuff. I did one of these last year too for that fundraiser...again, found snowflake plates, cups, napkins, placemats, little hors d'ourvres forks, snowflake shaped candles at Christmas Tree Shop.
I love doing baskets. If I could figure out a way to make it a business, I would.