Zip ties are useful for managing cables, but you can only use them once. If you're looking for something less permanent, Instructables user seadraggin shows us how to take aluminium wire and paracord to make assorted lengths of ties.
The process is simple, but it may be a bit tedious if you want to make a lot of them. Just strip the paracord fabric off its wire innards, slide in the aluminium ground wire, and seal the ends. Because you can buy both parts in bulk, you can make plenty of these inexpensively, and they maintain their shape well while holding your stuff in place.
DIY flexible tie ties (CHEAP) [Instructables]