Apparently, overloading the washing machine can cause holes in your clothes, and you should always be sure to turn items with beads, buttons, or other embellishments inside out.
You should also avoid overusing bleach (if you use it), as it can cause holes in your clothes.
Finally—and yes, this is going to sound terribly obvious—be careful around rough surfaces like brick and stone, as well as objects that might protrude from these surfaces, like nails.

Do you ever find yourself with clothes with holes in them? Let us know in the comments.