Originally Posted by biggness
I'm probably worse at guitar than you but one thing I have going for me is tons of practice.
As far as a really simple "getting limber" kinda warm-up that uses a metronome is concerned, I just do 1-2-3-4, alternate picked, up each string, slide up one fret and play it in reverse back down (so, 5-4-3-2). Set the metronome pretty slow to start and you want to time it with one "click" per string (this makes it really easy to lock into the click). You can keep ascending as high as you feel you need to, then increase the speed on the metronome until you either max out or start getting sloppy, then go back to where you feel comfortable and focus on that. This sounds boring and like it takes forever but I'm impatient as hell, so I usually only do a few passes and bump up the speed 10bpm at a time. 5 minutes of this here and there per practice session is invaluable.
This did wonders for my alternate picking, clarity-wise and it also forces you to use all your fingers on your fretting hand. The purpose behind doing it as a simple chromatic walk is because you're concentrating on one thing at a time, rather than trying to memorize a scale/shape while you're supposed to be observing your technique. Once you've got that "down", you can do the same thing but with scales. (EDIT: Also, you can do the exact same exercises, legato).
As far as scales are concerned, I recommend starting with the major scale and learning at least the first two positions. Then, you do a similar exercise to what I mentioned before (one "tick" on the metronome per string, ascending then descending) but instead, you play the first position of the scale up and down, then the second position up and down. Once you've got that down, you can do the first position up, second position down and so on. This does helps speed and dexterity and helps to you memorize the scale in more than one fingering (when you get into playing non-scalar runs later, you'll thank yourself).
If you're to the point of practicing sweep picking with a metronome, I usually do one "click" per "direction". So, "click" *ascend all the way up* "click" *descent all the way down*. For me, that's easier because having more than one "click" per direction causes them to possibly land on odd notes and that's a little confusing unless you're really used to things. (EDIT: And don't be afraid to go reaaaaalllllyyyyy slllloooowwwww. Super clean technique holds up under speed. Don't let even a single sour/unfretted note pass)
As far as working with a metronome for rhythms, I haven't done a lot of that since I was younger but I'd usually do either "down-up" "down-up-down" or "down-up-down-up" per "click" depending on what kinda phrasing I was working on. Same deal... increase the bpm of the metronome until you hit your peak, then dial it back and work there. Don't be afraid to call it a day at that speed because 1.) playing that same speed or faster will obviously becomes difficult as your muscles fatigue 2.) over time, your endurance and speed build up, so you'll reach the speed you want over the course of several sessions.
Also, you've survived 15 years without developing tendinitis but incase that's just by luck, I'll mention to NOT tighten your forearm/bicep... remaining limber actually allows for you to go faster overall, you can play longer without getting tired and you won't become a cripple. There's a great section in Guthrie Govan's Creative Guitar 1: Cutting Edge Techniques
. I'd actually recommend that book/CD. Great exercises and tips on technique at a very intuitive pace.
I'm sorry if anything I said sounded remedial or anything. Figured I start things off by explaining some basics.