I'm keeping my penis, and I want it to function. I like cute skirts, too. For the most part, I don't tuck, per se. I look for panties that have good elastic around the leg. I pull the back of the panties up first, point the head between the testes, then pull the front up. There's enough of a bulge that I won't wear pencil skirts, but anything with more volume works.
One trick I learned recently is that women hang things from their waists, where men hang things from their hips. If I hike my a-line skirt up a bit, the fabric hangs away from my body, and the bulge vanishes.
I had an idea a little while back to paint the inside of panties with rubber cement rather than use tape*. This was confirmed by a friend of mine who dated a cross-dresser. I consider that source suspect, as he was only doing it for an hour or two at a time and (a) didn't mind pain for that short of a duration, (b) didn't have to function in day-to-day life (e.g. trips to the bathroom). I'll experiment with it some time, and if I like the results, I'll write it up here.
* To be clear: I mean, let the rubber cement cure before wearing them!