This is pretty basic, but works great and keeps any liquids and dust off the heads.
Because my kit resides in the garage and the door is constantly being open and I do wood work as a hobby. Dust will always be in the garage. Also, because I cant always get out and play everyday, they end up sitting for a few days.
My solution was to use shower caps, they are water proof and dust proof and they fit 12" - 8" toms perfectly, come in a variety of colors too. And they are cheap too, I picked these up at a dollar store.
The pattern is vivid, but so are drummers!