First, you aren’t the first.
second, I found some pink masking tape online pretty cheap. when I am launching a bunch of rockets, i prepack them at home and i use the pink tape ONLY for holding the nose cones on, and I leave an obvious folded back “tag” so HOPEFULLY it is really obvious when I take it out to the pad so I remember to remove it before launch. Yes, this is the poor man‘s “remove before flight” flag. So far (and I am not going to push it) it has worked well for me. The pink color is just because it is more likely to catch my attention, the Manila masking tape I tried and missed.