Maybe get someone to video you when you ride and watch the videos and critique your riding yourself when you have spare time?
You can do different stretches while at home and when you first get on take your time to walk and get a feel for the saddle again!!
Keep your body fit by doing some stretching and balance exercises every day, it helps you maintain good posture when riding. I also agree with Mariia and Shaun, knowledge of the theory behind exercises helps understanding them and will make it easier to perform them 😊
Do more research on different topics related to horses and riding, the more knowledge you have, the more you can practice during your riding days and the process will go faster:)
work on theory and improving your own ability some days i stretch out my heels on the bottom step of the stairs