Guitar skills: Jimi Hendrix makes great use of trills in the breakdown in Voodoo Child. The technique boils down to a series of fast hammer-ons and pull-offs using just two notes.
Practise slowly at first, ensuring that your timing is even and steady. Most important is a good ‘snap’ movement as you play the pull-off so that every note rings out loudly. Support the third finger bend with your first and second fingers for maximum strength and leverage on the string.