I've never paid much attention to the jib telltales. I've always focused on the main.

Now on the mono's where the jib is actually more powerful than the main, thats another story.

What I do, is trim the sail all the way in going upwind... point up until the top telltale begins to break, then back off about 5-10 degrees.

off the wind, well, it depends if you're running a chute or not.