A small moustache comb helps with the yukkies. I've had a 'stache for as long as I can remember. As for trimming it; my barber does it for me.
It's been said some already but I found with beard growing in general, that it's best to grow then shape. Also the comb straight down, and trim the bottom is best for the classic, "Bert Reynolds" 'stache. Basically the longest hair should be at the top. Though you could trim on top, under the nose.
Speaking of mustaches, my youngest son & I are having a competition on growing a handlebar. I just started growing my 'stache back on Nov 1, so he's a several months ahead. I'll need to check in with Steve (@swarden43 ) on some tips.
I don't doubt for a moment that the result on my upper lip will nothing like the one on the Czar Nicolas' lip in the photo. Mine will no doubt be une petite mustache grise!
I have no idea what mine will end up looking like. But.... I am going for something like these. MINUS the beard.
And this guy's whole retro look is awesome. Hair and stache. But I'd never pull off an epic Handlebar like that.
<---------------- that one was at about 6 weeks. I tend to keep mine longer, carry a handkerchief and comb to get the crumbs out of it. I've never tried a handlebar mustache.
I'm going on 3 and a half weeks now and it's starting to catch foods. I had cinnamon rolls today and the glaze got in there and made a real mess. Lol...
DO NOT TRIM. You'll go through what I call the Geraldo stage where it's going to look ratty, but let it go. Really you can start at that time with some moustache wax to start training it and keep it somewhat under control. On rare occasions I will trim the ends; seems one side grows ever so slightly faster than the other.
We did a western theme murder mystery dinner for Halloween, so the wife let me forgo the circle beard for the occasion. This was as close as I could get to handle bars in the 2 weeks notice I had.