I've been using Southord picks but anything that isn't going to bend or break on you is good. Do yourself a favor and shell out for a little more than the basic packages or else you'll find yourself limited in certain situations. Not that you have to start out with a thousand picks or anything like that but get a good variety so that you can figure out what you're most comfortable with.

I've had the same problem (or at least it felt like it, I don't have any cut-away locks.) Here's my poorly thought out yet efficient strategy: Try different picks until I find one that fits better or until I get frustrated, then try to rake angrily until it pops open or I get more frustrated. If I fail with the picks I break out the bump keys or if it's a padlock I break out the shims. High success rate but not exactly skillful or elegant.