Step 1: Materials
-The Core- This is one of the most important parts of the mallet. the core will play a huge part in the sound of your mallets. A harder core, such as a wooden craft ball, would be good for a pair of vibraphone mallets. A softer core, such as a bouncy ball, would be great for a pair of marimba mallets. Also, I've heard that the rubber end to a pool cue, (that little half circle) make a good marimba core, but these are harder to find.
-The String- Most kinds of yarn/string will work for your mallets. An acrylic yarn is good for beginners, as it is cheap and easy to find. The professionals use a wool, of wool and cotton blend. If you can LEGALLY attain it, hemp makes a very long lasting mallet head. The thickness of the string will change the number of wraps needed to make the mallet head. (Thinner string, more wraps, thicker string, fewer wraps)
-Creativity- Many of the things needed for making mallets are to be done to your personal taste.
-Disclaimer - I do not use hemp in my mallets. Use it if, and ONLY if you can obtain it LEGALLY. I will not be held responsible if you get in trouble for making, using, working with hemp, and/or hemp mallets.`