First week home after adoption, my mixed boys expressed an interest in my Sonicare and me in feline hygiene and nutrition. I brush twice a day and brush them at least 5 times a week in the morning as once or twice I might get caught running late or unable to get to all of them before I continue the morning routine.
I use CET poultry and experimented with beef and seafood on Mon night and Tue AM of this week but that did not go over so well. They don't taste and smell as good so I'm sticking to the poultry flavor.
I start with the small brush, get them to lick and accept it, then they open their mouths so I slip the brush into the molars and they start chewing and grinding on the brush. I then gently inch it forward and then back again while they chew, repeat on the other side, then both sides once more. Then the final is they use their front teeth to chew and in between the licks, get as many rubs on their incisors as I can. The whole process takes about 3 minutes per cat with taking care to move the paste somewhere they can't reach.
Isis is still too young to understand "boundaries" around Ra so I usually try to brush his first while blocking Isis either locking her out of the master bath or making sure to move her down to the floor.
This keeps their teeth in better shape and drastically reduces stinky breath or morning mouth. Nothing worse than getting a lick by a dog or cat and going UGH what is that lasting smell? Brushing MIGHT add years to their life because later age infections will quickly pass from mouth to immune system and organs.
As far as technique goes, don't force it and get them used to having a hand on their shoulders. Get them to lick the paste off the brush and keep working towards trying to gently move the brush to their molars. Eventually, they will get to a comfort point where they will readily wait for brush time to gnaw on the bristles while you move the brush around their mouth. It took my boys all of a week tops before they were heartily chewing and brushing on both sides of the mouth. It took Isis 2 days and being a teether right now, she readily chews on it because it tastes and feels good!
I face them during brushing so my left hand is on their shoulder blades while the other has the brush. Why I do this is because if they start head tilting too far to one side, their whiskers will feel my arm and they will not keep pulling back while being brushed. If they accidentally get the brush too far to the tongue they will open wider and attempt to move, so be prepared to make multiple attempts of getting all the teeth, even with a small brush. And be prepared to fight tons of licking in order to get the incisors in front where you might have to gently hold their head or cheek in one hand while wiggling the brush across the incisors while their tongues are going non-stop.