Line plant pots. When repotting your houseplants, cover the drainage hole with a coffee filter before adding the soil. Water can easily drain away when you water your plants, but the filter prevents soil from leaking from the bottom of the pot.
Galvanized Metal Tubs as Planters Drill several holes in the bottom and put in a layer of gravel before adding your soil and plants. Once you drill holes in the bottom, use fingernail polish around the edges of the holes (inside & out) so the galvanized pots don't rust.
Drill a hole in the side of the bottle near the bottom and feed your lights in through the hole. Plug it in and you've got yourself a rather novel little bit of mood lighting. Add colored or clear stones/gems.