A lot of times when I use some kind of tape roll, I just fold it and then when I want to use it again, I spend some agonizing moments trying to find the beginning of it.
What can I do to find the end of the tape more easily?
Fold the tape back on itself. One fold works great, and you don't need a lot. One to two centimeters is enough.
Doing it a couple of time will give you more to hold on to making it easier to peal, but will waste more tape the more you fold.
I have found two solutions to this problem:
Folding it over is definitely the best idea. For when you've forgotten to do that, run your fingernail along the corner of the tape for the full circumference of the roll. Your nail will catch on the corner of the tape end. If it doesn't then run your fingernail in the opposite direction.
If someone was careless enough to not employ one of the preventive methods above to make finding the end easy next time, then you can try:
I have an easy solution. Bend the tape backwards so that it will not stick back to the roll by itself. Then next time when you use again, it is still sticking out. I made a video showing how: https://youtu.be/QeGyVtNXf7w
If somehow I forgot to fold back the end of the tape I slide the blade of a snap off knive aroound the roll of tape until I meet the end.
Then I carefully lift the end of the tape with the blade.
Put it in a tape dispenser (available in various sizes from tiny up to and including hand held parcel-tape "guns") - it sticks to the blade so the whole question does not even arise.
Take a razor blade or utility knife and slice through the first layer of tape. Then peel it off from wherever you sliced it; you can use the blade to lift the tape as well. One way or the other, you'll find the end.