The slowness of my trills is getting annoying. I am able to play Blue by Yngwie Malmsteen but yet fail at doing the trill in the intro. How can one practice to make them faster? Endurance is not an issue I can keep trilling for 40 seconds at my top speed without tensing my fingers.
Starting at a slow tempo hasn't really helped, what other tips are there?
Trills are (unfortunately) one of those things that only constant repetition will aid.
Your body is not naturally used to the movements required for trills. When you constantly practice them, your brain will eventually pick up on the movements and it will become natural to you. Note, by "constant", I don't mean a two hour crash course session playing nothing but trills will get it down. Everyone is different, but just devoting a portion of your practice time to trills each day will vastly improve your performance of them.
One way to do this is to take pieces that you know fairly well (i.e., not sight-reading) and insert trills in various places as you play them. First, you'll get a feel for where a trill sounds good, and secondly, you'll learn to smoothly use your trill in a piece.
Don't be afraid to push your limits. If you never do, you'll never improve. However, don't push them so much that your technique is lost. If you're pushing yourself so hard that you start sacrificing technique for speed, you're not improving. Remember, practice does not make perfect. Practice makes permanent.
Bad technique takes years to hammer out. More importantly, bad techniques can possibly lead to injury (RSI). If you feel pain at any point, stop. There's a good chance you're doing something wrong. Examine your technique. If it's not apparent at first what you're doing wrong, get someone else to take a look. Getting faster right now is not worth the pain of relearning or causing harm to yourself.
Start small and work your way up.
Start with a hammer-on, for example, on the A string between frets 7 and 9, between index and ring fingers. This is probably the easiest place to trill, at least it is for me.
Get that hammer-on good and solid. Try your best to make it faster.
Once you master that hammer-on, immediately do a pull-off, and let the lower note ring out. 797..... get it as fast as possible.
Then start adding the 9 at the end. 7,9,7,9.... This is what I'd really consider a trill. Here you may find your speed decreasing or your endurance becoming a challenge, and it's a great place to stop and practice.
As Luke said, it's totally about repetition and practice and training your wrist and fingers to make that rapid movement for a long time.
By the way, a trill between two fretted notes is often far easier than trilling between a fretted and open string (such as 0-2-0-2 type patterns, common in SRV/Eric Johnson type licks). It's actually a different movement because the pull-off is more forceful, so I'd start with the two fretted notes first.
Here is a great exercise I used to give to students as they get started doing hammer-ons and pull-offs, just pick it the first time and make a trill drill out of it.
Starting in the first four frets, where the 1st finger is on the 1st fret, 2nd finger on the 2nd fret, 3rd finger on the 3rd fret, and 4th finger on the 4th fret: Do every possible combination, in time, with a metronome. Start on the Low E for one measure, move to the A string for one measure, D string for one measure, etc., so you also incorporate horizontal movement.
Groups of 2: 1-2, 1-3, 1-4, 2-3, 2-4, 3-4
Once you feel that that is solid in one 4-fret position, start incorporating vertical movement. Every time you change a string, move up a fret. Go up as high as you can, then descend a fret on the way back. This will give you a great deal of endurance, coordination and give you a practical way to work on this. Try bumping up the metronome 1 BPM at a time, and work it out!
Go back to the fundaments - practice your hammer-on and pull-offs. Get it solid. Make them sing! Ensure that the attack volume of these notes is equal to normal attack volume you usually do. Only the nuance of the ASDR should change, not the actual volume of the produced notes. This ensures you've got the right technique to really nail down (pun intended - once removed {hammer-on, pull-off}) these trills.
Watch yourself doing it.
Are you fingers moving any more than necessary? Go for the goal of small and slight movements, this requires less work = faster movements = faster and easier trills 'til the cows come home.
