Millepede Cable Ties are at first glance just regular zip ties—until you discover they can be unlocked and reused. And because the fastener works through any of the holes in the tie, you can cut off any excess after tightening it down and reuse it.
I can't believe I've never heard of these. Even if they don't hold as securely as zip ties, they'd still work for 90% of the things I do.
Millepede Cable Ties [Cool Tools]