The broken record playing in my lessons

My lessons as of late focuses on a few select things:

1) Keep bow *in* the string. Sounds logical enough but so hard to do. When I sound bad, I can almost always pick it out to be this particular problem. I used to think that keeping the bow in the string should be an easy enough task but I think it's actually harder than it sounds. It takes a certain amount to strength to keep the bow in the string...strength that is built over years.

2) Related to #1 - don't pick up the bow when crosing strings. Sounds obvious enough but I cheat on this in the most subtle ways. Just the tiniest of lifts when crossing strings will throw the sound off. arrrrrggghh

3) Slow down the bow changes. If your left hand needs to move fast, it doesn't mean that your bow changes need to be fast as well.

There you have it! The three things on the broken record playing in my lessons. I'm happy that I can pick out three things to correct whenever I sound bad. What about you? What's on your broken record? Do share!