First would have to be the crotch squeeze. I find it hard to keep my hands off my crotch when my diaper is swollen. Second would be the bum rub. While I generally try not to number two in my diaper it does get swollen in the back from pee.
I do crotch squeeze and bum rub. My SO do to me same, depends in access. When I wake up diapered next after some hard day(s) , she will usually touch my diaper ( sooner or latter).
And tell me to put a new diaper after removing soaked( if used) and shower. To stay in diaper if I want.
If I'm not wearing trousers over my diapers and rubber pants, my wife uses her fingers to check under my leg opening. Sometimes she will squeeze my crotch instead, or after she's tested under a leg opening just to have a bit of fun. If I have pants on, she pulls the back of my trousers and my diaper and rubber pants and puts her hand down the inside of my diaper until she feels any wetness. Since I only wear cloth diapers, if I am wet, the diaper is wet all the way up the back, or front for that matter.
My wife does not check mine, but I have done the crotch squeeze, hands down the front, and the finger under the leg gathers. This may sound ridiculous to those of you who are fully continent, but there are a lot of times when I have no idea how wet I am and usually find a private place to check my diaper.