This article is pend with 30 round aluminum USGI AR-15/M-16/M-4 magazines in mind, but it can be made to work for most any magazine.
For a more professional look, check out magpul.com
Step 1: What you need
2. Paracord, aka 550 cord. 6"-6.5" per magazine
3. 100mph tape, duck tape works to, gaff doesn't hold up well.
4. A cutting tool. for paracord.
4. FIRE! lighter works just fine.
Step 2: Prep
Pic2. Cut 6" to 6.5" of paracord.
Pic3. Melt the ends of the paracord with the lighter. Because the paracord is made of nylon (a form of plastic) it melts (rather than burns) when exposed to flame. Hold the flame to the paracord until a decent blob of molten plastic forms. Remove fire and allow to cool for a few moments.