My bathroom needed some green to break up the blue. I found this great article on planting cacti in glass containers with sand. I went to a nursery and found a cacti guy. Who knew they would have a guy like that?
Step 1:  Find the right container (mine were Goodwill finds for $1 each)
Step 2:  Talk to your local cacti guy - take containers as he/she will be able to tell you what will and won't grow well in the container and what height to plant.
Step 3:  Buy cactus potting mix (yes) and gardening sand (not beach sand - not the same)
Step 4:  Fill container part way with sand making a deep bowl shape in the middle
Step 5:  Spoon in just enough cactus potting mix to cover bottom and sides of divot
Step 6:  Insert cactus with as much of it's original soil as possible
Step 7:  Cover potting soil and tap down around cactus
Step 8:  Add decorative rocks your family brought your son back from far off places
