A while back we shared a niec little clip called the Nice Clip. It is a clip that attaches to the lens cap and make it clipabale. It really is one of those smack-me-on-the-head-for-not-thinking-about-this kinda of ideas.
Luckily, its simplicity makes it a good candidate for a DIY version. I guess photographer Sean Ragan thought the same. Using a small lapel clip and heavy duty outdoor mounting tape.
I wish there was a tutorial on how to make those, but I guess it is just: 1. put tape on clip; 2 attach clip to cap.
Going for something a bit more fancy? You can always build Benvelo’s lenscap saver (plans here). Or use Sugru to slap a clip on the cap, like in the movie below