LED throwies are fun and all that, but can be quite expensive to build, at least in some countries. (for proper throwies you need magnets + batteries in addition to the leds) And because throwies don't have resistors, they tend to burn out a lot quicker than real led systems.
But yeah, that would work. But it wouldn't be what I'd call a simple solution. Unless you're going for 2DOF where you only need one led. For 3 clip/cap systems, it's cheaper to buy a led light series with a battery holder (on/off button too!), move the leds to the right positions and then just black out the unnecessary ones. That way you don't have to mess with any wires or add new resistors and such. Something like
this but with fewer and better leds.
Proper builds aren't that difficult either, considering a lot of people on this forum have done half the job for you. But you can start small and experiment from there.