Sensation Play
The anus is a bundle of super-sensitive nerve endings, and therefore is a perfect candidate for sensation play. Here are a few ideas to get you started.
Paint brushes. I love paint brushes over something like a father, say, because they have a nice handle and that makes it easy to target and tickle or pet JUST the right areas.
Silk. A piece of silk slid over the bottom and through the crack to tease the anus can be quite delicious.
Chain. A cool length of chain slid along the crack, along the sensitive anal opening.
Wax. Of course, use candles/wax made specifically for wax play. They have a lower melt temperature, and are less likely to burn. Keep wax play off the anus itself, as it is more sensitive and could burn.
Wartenberg wheel. A metal pinwheel with a handle, great for pain play. Don’t press too hard. Those things are sharp!
Tiger Balm. Be VERY careful with this, just as with figging (discussed in another section).
Metal or glass toys + hot or cold water. Heated or cooled massage oil or lube. Temperature play can be all manner of fun.
Really, anything with texture can add to sensation play, just remember if it’s porus and can’t be sterilized, then it can only be used with ONE butt, ever, for safety reasons.