Exercises to help improve seat and leg position.

Hi All,
I had my father take some videos of me riding today; I looked at them and I looked HORRIBLE! I've been riding for five years, but with college I have few opportunities to ride...and I've noticed/felt that I am not as stable as I used to be. My right leg is all over the place when I canter, but the left one is solid. Trotting is a whole different story. I'm fearing that I'm getting back into my old riding habits of not gripping the horse. Knowing from several people (and my own experience) I know that my horse rides like a Cadillac, so I figure it's me just getting out of riding shape. Thankfully my boy is a good sport and didn't do anything despite my bad posture!

Any tips? What are your opinions of doing two point and stirrup-less in the saddle? ANY exercises on or out of the saddle would be a great help.

Thanks again :)

For solid 2 point, I've been trotting and cantering around (mostly trotting since it's harder) with my stirrups abnormally short.

For overall seat, I've been doing sitting trot without stirrups just to try to get the correct muscle memory re-established.

Other exercises are,

While trotting, post every 3 beats, not two. For added difficulty, mix is a few steps of two point.

Trotting and cantering grids with either very loose reins or no reins so all you have for balance is yourself.

Riding with one leg out of the stirrups, alternating every so often. This one more than any will show you which leg is doing most of the work.

Off horse, pilates. Ouch but they work for stronger core.