I vary between them. I ask him to do some things, like stop, back up, sidle left/right, come onto the bit, slow down, then walk on. And when he does a couple, I give him a long rein and let him go on the buckle for a bit. But, I change things up with the contact. And, it depends on how he feels. Whether he's worrying about things in the bushes or not.
If the horse is tripping a lot, then you might have to ask him to walk with more push from behind and more balance . If you do, then try to find other times to be able to offer him a long, loose rein ans a reward. Certainly, when standing around.