If you’ve never really tried one for an extended period of time, you should use a thumbpick for several months to see what it’s like. Of course you can play fingserstyle with a thumbpick, but you can also hold it like a flatpick for strumming chords and playing single note runs. Try wearing one for a couple of months, and just hold it like a flatpick most of the time. After a while, you’ll find that you are using a combination of playing with your fingers and holding it like a flatpick – the best of both worlds.
Using a thumbpick is obviously great for folk / fingerstyle on acoustic guitar, but you can also use it on electric guitar to great effect. The thumbpick lends itself to roots music of all sorts, including blues and country. Chords come alive with dynamic control in jazz, and riffs can really pop when you’re playing rock. Even bluegrass – that traditional bastion of flatpick on guitar – can benefit from a thumbpick… and as mentioned you can still flatpick with it.
For the most part, you don’t give up much when using a thumbpick as a flatpick, though certain techniques like picking/pinch harmonics won’t come off the same way. You may not be able to get quite the same dynamics, but overall what you gain will probably be more useful. (As another bonus, because a thumbpick is secured to your thumb, you won’t drop it.)
As noted in the video, I prefer Fred Kelly’s Delrin Slick Picks – generally using medium for acoustic, and heavy for electric. These picks have a snug fit which may feel too tight at first, but they do loosen up a bit after you wear them for a while. They also make a ‘large’ size version of the pick, and of course there are many other brands / styles that fit differently which you can try. (One trick – that may not work with all pick materials – is to run them under hot water for a while, and then you can loosen / tighten the fit.) Use your common sense and intution – obviously avoid thumbpicks that are outright painful, but be willing to try out ones that are merely uncomfortable for a while, potentially adjusting them, to see how you like them.
One final note – generally I do not recommend thumbpicks for beginners unless they only want to do fingerstyle guitar. I think it’s better to develop your technique with a flatpick and then add a thumbpick later on. I may change my mind on this in the future, but for now that’s how I feel.
Fred Kelly page for Delrin Slick Picks – http://fredkellypicks.com/product/delrin-slick/
Note – this page is more for reference. To order Fred Kelly picks a few at a time, try the Elderly link below. They also have other brands / styles you can try.
If you want to try out different picks and just order a few at a time, Elderly has a great selection – http://elderly.com/accessories/cats/PKTB.html It might be good to order several different sizes / shapes styles to see what you like.