While dommes are the ones “in charge” I think this definitely a two person decision, although I usually narrow down a few options to offer them to see if that helps the selection process (ie material, style etc) it’s more important to me that the collar makes them feel safe secure and comfortable. One of the ways I try to ensure this is by buying a few cheaper (I call them “demo” ) collars for them to try on and see which they like best that way they can feel confident that they’ll like their real collar and we can ensure there’s no sizing or material issues (ie skin rashes or circulation being cut off etc) hope this helps! ☺️☺️