Reddit reviews Victorinox Black Channel Knife Polypropylene Handle, 4 Inch, Multi

It's just experience and practice. The only equipment you might want is a channel knife—it's basically a little V shaped blade that lets you cut spirals out of a citrus peel. The easiest ones to use are where the cutting direction is parallel to the handle (like http://www.amazon.com/Victorinox-Channel-Knife-Polypropylene-Handle/dp/B000MF46H6) rather than perpendicular (like http://www.amazon.com/OXO-Good-Grips-Lemon-Zester/dp/B00004OCJO).

Then just buy, like, a dozen lemons and start cutting twists. It takes some practice and a steady hand. If you want to make really nice spirals, you can then wrap the twists around a barspoon or any other stick (even a straw). You can find videos online if you need help.

I personally don't usually do twists, I usually just cut a thin swath of rind. I like this because you can express the oils from it in a very controlled way, and I think a swath of orange or lemon peel looks really nice in a drink (like http://www.foodrepublic.com/sites/default/files/imagecache/enlarge/recipe/Classic%20Negroni.jpg instead of like http://caskstrength.files.wordpress.com/2011/12/negroni1.jpg).