condition the glue...
 

Good Idea for the Duct Tape - should be the cheapest option out there. To make it easier to come off, first press and remove it on some fabric (jeans, shirt, pants) a few times. This reduces the stickiness of the tape, making it easier to take off.

I use bandaids, I find that if you use the entire bandaid, it will eventually fall off. But I cut them into thirds, dispose of the middle cotton gauze part. And use the stick part on each nipple. Works well for me.

Thanks. Another solution is the home remedy in Post #6. I like that better as bandaids tend to fall off when I sweat.