I often use the solid-wire trick. I'd note that if you use multiple
turns--two or three or four-- it will hold much tighter than a single
turn, allowing use of easier-to-handle smaller gauges to hold the same
load. It's also a lot easier than a tie-wrap to UNdo when the time
comes--no tools required. Easily available in black and white (in the
US at least), and other colors if you want. Scales to different sizes
well, too. Not that I don't use tie-wraps too, but sometimes they
aren't quite the right choice. Oh, and I've recently gotten some
easy-release reuseable tie-wraps -- black, and reasonably easy to use,
though a larger "knob" of plastic at the latch point. Dunno how many
times they can be released/re-used yet.

Cheers,
Tom