Posting trot

In my lesson last week my trainer had me squeeze while I was up in posting position as opposed to when my bum taps the saddle. That had me wondering when others squeeze their horses forward?

Hmm, I honestly don't think about it anymore... I just do it on instinct, I guess! Now that I think about it, I generally squeeze when I'm sitting down, as opposing to standing up, just because it's easier... but I'm sure either method works well.

I don't leg on with every step posting. That will totally dull the horse out. I put leg on if the horse is falling out of rythm, and I need to freshen him up,I put my legs on quickly and with a kind of "tap, tap" with my ankle bone against the horse's side. I expect him to surge forward. Then I won't put any leg on at all , until he starts to do something I didnt' tell him to do, like fade out again.
I think I do it when seated, but it's so automatic, you know.
For

Yeah, I'm so used to squeezing while sitting that its so awkward when I'm up. She's having me try it to see if I can keep my momentum going better. She said that's when she squeezes.