When my father taught me how to drive, he took me to quiet hilly roads and we did things you wouldn't normally do in everyday driving but really got me moving forward in leaps and bounds with the manual concepts. The best was to hold the car with the clutch [instead of brakes] on an incline. Then he would say, OK move forward [more gas, slowly letting clutch out/engaging] then hold it, then go backwards x feet [disengage clutch], then throttle and engage, hold, etc. Working up and down gears and learning good throttle and clutch management, on an incline, is brilliant training.
Great comments here on down shifting. I didn't realize it was such an art, or a ballet if you will. Now I will be mentally grading myself to see if I am actually doing it in the steps described.
I especially think heel/toe training at the onset is smart. I forget to do it, until I need it. NOT a ballet on my part.