This first one I made by finding a mesquite driftwood looking piece in the desert. I then soaked it in water w/ a bit of bleach to kill off any critters inside of it for a couple of hours. Then I scrub it to remove any dirt and loose bark. I let it thoroughly dry for 2-3 days. I then put three coats of polyurethane with a sponge brush. And then let it dry. That's it.
They second thing I made is just a little air plant (bought on etsy), that I put inside a little candle holder and rocks (both from Michaels). Air plants are easy to take care of, especially in humid areas. In drier areas you need to lift it from the container, dip the roots in water a bit, then let the roots dry and return it to it's container. In humid areas, you don't need to "water" it as frequently.