I was using a travelmate for quite awhile before I 'came out' to myself. Mostly for camping (and larping - ha ha). Just... yesterday, actually; I went out and bought a regular old medicine spoon and some clear tube so I could make a new one, because I had to start using a port-a-toilet at work (ugh).
When I first started using the travelmate (which is pretty much a really long medicine-spoon, already cut at the end, and slightly softer) I had a ton of trouble getting it to work 'right'.
At first, I wasn't holding it in the right place when I tried, and that's one of the reasons it leaked. If you know it's in the right place then don't worry about this. Otherwise, strip, stand in a bathtub, pull all the skin back out of the way so you can see, and piss on a hand mirror so you can figure out exactly where it's coming from. Yeah, I actually had to do this. Even anatomy charts weren't helping me much; I was holding it way too far forward to work properly.
Also, how did you make your STP? If you just drilled a hole in a medicine spoon, it might not be emptying fast enough, and overflowing because it's backing up. I ended up taking a hot knife and just cutting the entire end of the medicine spoon off, so this wasn't a problem anymore. Attach some clear plastic tube to it so it's long enough to use practically. Tons of vids on youtube that show this well.
The other thing I had trouble with, was actually holding it too tightly against myself. if you press it up too hard, everything gets sort of pinched. I'd end up pissing all over my hand when this happened, so if you feel like you might be doing this, try to just hold it comfortably in place, and not so tight.
Good luck, man. I hope something here helps.
