If history is any example, the 5.10 you do today will be rated 5.11 in a few years. As has been said above, find what you like, be it types of climbs, location of climbs, particular friends to climb with, and go for it. You'll be pushing the envelope a lot quicker if what you are attaining is what you enjoy.
Good advice upthread. As noted, strength to weight ratio, in addition to lots of practice, is critical. Re read Jstans excellent post.
Dave Kos, the company is called "5.11 tactical" cause that's what Royal Robbins named it.
"I asked some old people ...they were ..like...35...gnar is that stuff between yer toes after a long day of climbing without socks."
I believe that "the Gnar" is actually located under yer testies and under yer foreskin, and is substantially more prevalent on a 3 week climbing trip sans any showers. At least that's what I heard. "Shredding the Gnar", is what a dude does when he can't get a woman and is in "need".
As far as anyone who could actually "shred" rock, John Long was the only known animal, and he's currently laid up.
Man worked out this week and thought i ate half decently, only to step on the scale after a week to see i gained two pounds WTF, discouraging to say the least. Oh well stick with it and see what happens next week.
Finger strength and technique are more important that your weight IMO. Yes the best climbers are usually wiry guys, but there's been thicker guys, not fat but not thin, who climb pretty well. If you are not built to be thin it is very tough to try to stay thin.
For training climb at your limit until failure. i.e. keep trying 11s and keep falling off them, don't just run laps on 5.9, just be careful of injuries (exercise the forearm extensors to keep them in balance with the flexors which get worked when climbing). Don't go for endurance, go for strength in your training.
Bouldering is an excellent way to do this type of training.
The hardest climbs I've done have been projects. Something I've tried over and over until I work out the moves and gain the needed strength from doing the moves over and over on different days until I get it.
Try harder climbs that are a style that you are best at. I'm best at slightly overhanging cracks or slightly overhanging blocky face climbs.