No...I made the mistake of setting a relaxed precedent at the beginning of my professional career. It took me over a year to get the "respect" level back where it needs to be..It's a funny thing, people can handle things being strict right from the start, but when you try to make it stricter, then the complaining begins...Have your policy, and make no exceptions ever...ever Even if it is your favorite student and it is the day before his exam...
I believe that the rules are there to serve a purpose and have no inherent value themselves.Hence, you are free to deviate with a good enough reason.I suggest a "rule" of thumb: when deviating the rule serves the same purpose better than following it, it should be a nobrainer. When the purposes are different, you weigh the cost/benefit. If your rules are reasonable and make sense, deviation should be rare. But if your rules are absolute and allow no deviation, then by definition they are unreasonable, and you are hiding behind rules when sometimes you should use judgement.
Okay, question.... Have you had to turn away a student, and resume the following week because their parents forgot to pay? I find it hard because it affects the innocent student, but I have done this once. And what do you do when you get the, "Can I bring it by tomorrow?"