Don’t ever increase something by 10 bpm’s unless you’ve been playing it for a long time. In my finger exercise tutorial I give tips about increasing speeds by that extent in a short amount of time. What you want to do, is practice the same lick over and over again for at least 5 minutes and increase the tempo by one BPM only. What happens is that if you do a sudden jump like that just because you got it right, your picking hand and fretting hand will tense up because they won’t know how to approach that speed. However if you only increase the BPM by one after 5 minutes of playing something, not only do you let everything retain muscle memory of what it’s doing, you are slowly acclimating your muscles and hands to an increasing speed. I relearned the Hail to the King intro with economy picking like Syn plays it. Yesterday I couldn’t even play it at 70 BPM. But I played it quite literally, for 30 minutes straight. Then I was able to increase the tempo to 90 BPM and it only took me about 20 minutes of playing it like that before it was up to speed. I have tried numerous methods of increasing speed and quite truthfully this is been the only thing that works for me. It gets annoying having to play something so slow for so long. But when I was struggling with an alternate picking run of 16th notes, I couldn’t even play it at 90 BPM. I did this method for only a few days and I was able to jump it up to 130 BPM in only 3 days. If you’re still struggling at a certain BPM even though only increasing it by one, that means you don’t know it enough. I always try to look at it like this: if you increase it by only one BPM each day and practice it for 20 minutes at a time in one month you’ll be 30 BPM faster but a hell of a lot more proficient and solid playing it! Just be patient with yourself and don’t rush things, you really want to make sure you know what you’re doing. If you need this kind of approach to practicing explained a little bit further, I’d be more than happy to Skype with you and explain it vocally.