Small raised poles are good for balancing the trot and keeping calm so they don't rush off and I found that lunging with side reins and long reining is extremely helpful

Lots of ground work. Especially using driving reins. But most importantly fun stuff to keep them interested and curious.

I'm taking him in halter and just walk around, or groom him or even just stay with him and talk : I want him to know me, don't be afraid, and trust me :)