10 Gallon Aquarium Decorations?

An interestingly shaped piece of driftwood is always a good bet. It looks natural and the twists and turns provide hiding places, as well as adding decoration. Just soak it in a bucket for a week, changing the water every day. Or, you can boil it for an hour or so (a lot of people say 15 minutes, but when I did that, it still released tanins like crazy).