Okay, I had a cactus farm in Massachusetts and the best thing for cactus is a pot that you think is too small. Out in the desert they are wedged in between rocks and hard dirt. The bigger the pot the bigger the root gets, not the cactus. Keep your cactus in the smaller pots, they like it better.
Also, if you cactus have aerioles (cactus needles) they get moisture out of the air and need very little water. If you have a succulent that has no aerioles, they need more water, like a burro's tail, jade tree or even Poinsetta. Yes, poinsetta is a cactus. All cactus are succulents, not all succulents are cactus.
They also do well with an occasional drink of miracle grow.
If you have an easter cactus, xmas cactus or any of those, the best thing for getting them to flower is to stick them outside in the summer under a bush. Don't touch them, let Mother Nature take care of them. When you bring them in at the end of the summer you will be amazed at how many flowers you get. Again, a little miracle grow when you bring them in and they will grow like mad.
Hope this helps