Depends on the horse for me...
Grace - lunge for a while, really until she is sane....one I get on her we walk for like 10 minutes, doing a lot of bending, circles, leg yields. Then trot doing same exercises, add.some ground poles. I trot until she is ready to canter, never a set time.
Sheena Bean - walk for about 15 minutes ( she is 18 so I like to give her.longer to stretch.) all around the property. Before I am ready to trot, I stop and flex her to my toe a few times. Trot, working on her being chill. She has headshaking syndrome so she is very tense. Do some long & low. I don't always canter her depending on how bad her headshakng is that day...it just makes all of the trot work I did go away... At the end of every ride, we gallop up the hill. Makes her very happy!
I was a dreamer
Before you went and let me down.