While choosing a slide may seem simple, it's actually far more complex than you might first think. Slides come in a wide variety of sizes, materials, and construction types. The type of music you play also makes a significant difference. A slide that you use to get a Keith Richards tone won't be the same as the slide you use if you want a Duane Allman sound. Even the type of guitar and amp you play will dictate your choice of slide.

If you're primarily an electric player, then a slide with less mass (i.e. thinner) would likely work just fine, since the amp is doing a lot of the work. However, acoustic players are probably better off with slides that have a bit more mass. You also want to experiment with the type of slide material. You can find slides made of copper, bronze, brass, glass, and porcelain. Of course, make shift slides (such as Duane Allman's coricidin bottle) are also popular. In the end, you have to experiment with a wide variety of slides to find one where the tone and fine are perfect for you and your style of music.