Hanging lights on branches. Go natural with a fat branch and hang a combination of ornaments and candles attached with wire. Use twine or strong fishing wire to suspend the branch from above. You might want to try hangers so as not to damage your ceiling.
From a single sheet of plywood and some dollar store bins she built this fabulous organizer. What a great way to use all that awkward space under the sink! Undersink Cabinet Organizer with Pull Out Baskets.