My SO was panicking about not being able to wear the top she wanted, it was cold outside, and the silicone pads would have been noticeable. I pulled out a roll of athletic tape and it worked perfectly. She told her cousins and they were surprised they haven't thought of that. Obviously not as effective with ladies with bigger bust sizes, but works in a pinch. It's also not painful to take off at the end of the night.
Also, less of an LPT, but if you don't know by now, people who run a lot, it'll save your nips too.