Woah! Look who it is! ;)
Ok sooo... tips for you:
When you ride, your biggest thing in posture is that your leg is to far forward! Remember, I know you heard it a ton of times but ear, shoulder, hip, heel. Stand up in your stirrups and then KEEP your leg when it was when you stood up. Automatically puts you in the correct posture.
When you canter, it's kind of like your posting it or something. Try sitting back and moving your hips with the horse. Took me forever and still don't have it down but :)
When you trot, it's kind of like you bump up when you post, try keeping your post longer. When you go up, keep it up for like half a second.
Ok, that's about it! You did really good and I'll send you the videos if you want. I have a lot:)