I agree that there is no way to actually measure it, but there are signs that I personally look for and follow to keep it in check. In reality, I don't worry about it a great deal because I almost never load to maximum. Getting to old to continually get beat up by recoil.
1. Primers that start to flatten or pimple around the firing pin strike.
2. Leading where I didn't have it before using the same bullet and lube.
3. Faster burning powders than are necessary for the load.
4. Any type of obvious scuffing of the case head.
5. When re-sizing seems to take a little more effort than it did last time I sized the same cases.
Probably forgot one, but as another poster said - by the time these rear their head, it's already too high, but certainly a warning that something isn't right.