Let's start with myself. I am a male [in the real world]. Okay, well, there's not much to say, since I don't have a TUG-partner! So:
>>> How did you discover the crotch-rope? (Internet, from-the-tier)
As a child, I liked (and still do!) the soft side of the inner arms [in particular] for unknown reasons. I have done weird things to mine - iced them, spanked them with a ruler, poked them with a needle (never went below 1mm in the skin - I would hate scars; and mostly nothing below the skin; so, don't worry! It was like playing doctor-doctor :X). This was before I was 10 even!
Some day, I had the idea of holding the arms, while those things are done to them! And I googled. Nothing special until 12 or so. I guess I gathered the terms "tied up" in this period. And pokemon is famous!
Googling "pokemon [name-of-the-girl] tied up" yielded images, with a crotch rope. This must be when I was 14. From then on, I have been intrigued. The rope does look "cute".
>>> If any, how have you tried a crotch-rope on yourself?
AFAIK, crotch rope for women works owing to the clitoris. (Consider this a lesson in anatomy, than anything sexual!) The equivalent part for men is the glans penis - the tip of the penis. Even then, women are the privileged species. I have come across tutorials for crotch-rope for men: but they require a lot of rope, and I couldn't get their point - they did not touch the glans penis!
My own version of the [male] crotch rope requires the wearer to have some amount of belly fat, and a boner. (If you are flat-stomached, you may still want to try this out.) I place a rolled-up cloth between the "bone" and the belly fat. And now, the rope can be taken over the glans penis. I prefer wearing briefs - but your choice. If you want, you can place some knots. The rope should just be "tight enough". I, almost always, "get off" with it; even by using a vibrator.
The cons for this include: the rope is easy to loose its "position" - but I hear that happens for women as well; can women confirm? The pros: wearing this and laying on your back is incredible!
>>> How frequently have you incorporated in your TUGs, since that first time?
Almost always. TUG-sessions for me [almost] always end up with me getting off.