I have some cuffs, but unfortunately they're too big, so I don't get that nice snug fit. Probably not getting the full experience when they're slipping up and down my arms and legs.
Collars though, mfff~
For wrist cuffs, so long as they don't go over my hands I'm good. The ones I have slide around a little. Thigh cuffs are never self supporting. If you're alone, never put a collar on tight. I actually put on my posture collar. I really want to find a good gag though, I kinda want one of these https://silencilicone.com/ but they're a little intimidating, and I really don't want to get the wrong size.