The string out of your chest image is good. Just remember that the string doesn't go straight UP. It goes upward at an angle forward, so it pulls you up and forward. Read Sally Swift's Centered Riding. That has to be THE single most helpful book on riding English ever written. If you like imagery, you will love that book.
Good reads and VERY helpful for someone RElearning how to do this. Without instruction. Genuine-love your name! Reminds me of Genuine Risk and the book, Wicked at the same time! I'll learn off you... K?