Trot to canter.

My mare races at a trot to get to the canter & its pretty annoying. I wish she could be at a relaxed trot & I ask her to go into the canter & she immediatly does it. Instead, I ask her to canter & she races to the fastest trot & then starts cantering.
I'm not into dressage or any english at all. I just want to teach her how to relaxingly switch from trot to canter during our everyday warm up.
I'm pretty sure its called a trot to canter transition.. or something. Haha.
Any tips on how to teach a horse to do this?

I have the same problem sometimes when my gelding wants to run lol. I suggest walking him for a little while, and when you ask for a trot, DO NOT let him advance to the canter until he's trotting slowly and calmly. This could take a while, so don't get discouraged

Have a specific cue to canter. Typically, it's the outside leg back and the inside leg at the girth, perhaps a "kissing" sound. Whatever you want to do, the cue to canter needs to be different. You may have to lunge him to teach him how to respond to a kiss if he doesn't already know. Once you know your cue and have established any vocal cue with him on the ground, now it's time to apply it. Trot him around at a nice, steady trot. Then ask him to canter. If he trots fast, slow him down the nice, steady trot you had going before. It may take a while. Then ask him to canter again. Repeat the process until he just picks up the canter. When he does, it is VERY important that you bring him back down to a trot and DON'T LET HIM BREAK his gait. If he breaks into the trot before you ask him, you'll have to have the trot to canter "talk" again. If you aren't experienced enough to feel him starting to think about breaking, it would be best to have him canter a few strides and then ask him trot and call it a day. Make sure when you do this, he is in good enough shape to go for awhile, and you have enough to keep at it. Just don't let him run into the canter, and don't chase him into the canter if you get frustrated.

Used to have this problem with my old OTTB. However, my trainer taught me an amazing way on how to help him find his balance so he can calmy and correctly pick up a nice canter. You also have to remember, the quality of the transition will refelct on the quality of canter you get out of it.

I was told to pick up a 20 meter circle and get the horse bending around your leg first. Get them relaxed and willing to work from the hind end. Also, by having them on a circle engaging themselves it will be harder to for your horse to hollow out and try to run off.
Keep on the circle until you feel your horse really listening to your aids and then ask them to move their hauches out. Kind of so that they are moving more with thier head/shoulders/front end towards the circle and thier haunches away. Don't even ask for a canter until your horse is moving off your inside leg and doing what you ask.
When you feel your horse is moving his haunches out, then prepare for a canter. Just before you come out of the 20 meter circle, ask for a canter. If he hollows out and you are running into the same problem with the canter transition as you described, put him back into that 20 meter circle and ask to haunches-out again.

I hope that wasn't too confusing. I found that this really worked on getting my old horse to get amazing canter transitions as the haunches-out gets them listening to your leg while stretching out their back and engaging thier hind end. I even use this with my current horse, his canter transitions are soooooo nice now! :] :]