Like Dood said. Practice. I'd also add compression and as also noted maybe changing the plectrum you use.
I've always used 1.0mm Tortex but lately I've been using .88mm, largely down to who I'm working with right now. So I have pockets full at the end of a tour. Saying that I'm really liking the .88mm because it's just a little more flexible. I've worked with a bassist that likes .60mm! a bit thin for me. The funny side to that is he used to throw them out but they'd never make it past the barrier so I'd collect them all after the show for him to use the next show.