I never ask for a recommendation letter. If the person gets exhausted as a reference, having a letter isn't going to help me, because parents aren't going to believe it's authentic without verifying it. Second, most of the parents don't have a clue what I do with their kids all day, do basically I would need to write the letter myself and let them sign, which is way too close to forging for me. Last, I have enough issues with parents reading everything I give them, and they're going to call my references anyway, so I don't see the point to giving them something else to read.