I feel your pain. Today I managed to get my tippet snagged on my nail clippers (what a klutz), but not near the blade. I made the next cast and thought, 'I should have checked that for nicks..." WHAM! For a brief second and a half I had something nice on the line, and then it was gone, along with my fly and a few inches of tippet. I'll never know if it was a trophy (I'm guessing not, but I see all lost fish through a magnifier), but I know why I lost it.

So I will heed your advice!