I teach agility and obedience classes for pay. I'm also a member of my local obedience training club, where I'm on the training committee and teach classes. However, we are a volunteer based club, so in order to get my own competition obedience classes at 1/2 price, you must be on the TC and teach at least 2 8 week 1 hour training sessions. In order to teach any class, you must earn a title on your dog (CD, CDX, UD), assist a trainer with a few classes and you teach 1 level below what ever title you have, ie: if you have a CDX, you can teach a Novice or Sub Novice class.
Though my training club is an AKC training club, they do recognize UKC, ASCA, AMBOR, MBDCA obedience titles and USDAA, NADAC, CPE, DOCNA & TDAA agility titles. They hold 1 AKC obedience & rally trial a year, 2 AKC agility trials a year, 2 UKC ob & rally trials, a NADAC trial, ATT test, APDT Rally and CGC testing.
I usually teach the spring sessions & summer sessions. When I teach, I usually do a Beginner 1 or Beginner 2 class, those are the classes I enjoy most.
In my area, you throw a rock and you'll hit a supposed "dog trainer". All the dog trainers I know have another paying job. Very few of them are full time trainers, those that are, teach at different obedience training clubs in the area. Also, these people that do teach full time are not teaching pet classes, their teaching competition obedience classes.