At some point in your dog’s life, there may be a time where a muzzle may be a good idea like in emergencies, in grooming situations, if your dog has bitten a person or dog before for examples. The time to teach a good feeling about wearing the muzzle is not when you need it, but now. I came across this video and think it is really well done for explaining how to do it.

Parents, YOU Are ALWAYS Teaching
Teaching happens whether we intend it or not. Our interactions cause others to learn positive AND negative associations with situations, and with us.