Practice, practice, practice. In the comfort of your garage (or living room).

It's very empowering to be able to fix your own flats, plus it's not that hard and an important safety issue (you don't want to be caught somewhere where you can't walk back from with a flat tire, or have to rely on strangers, etc.).

Get yourself the right tools for the job (search this forum for threads about what we carry on rides) and just do it!