I’ve taken to tying my Lightning cable up before putting it in my bag, but what I really should invest in is a retractable Lightning cable like this one from Scosche (which I read about on Tools and Toys).
I’ve purchased a few retractable 30-pin cables for myself from various sources over the years, and paying for quality in a cable does seem to make a difference. The cheap $3–5 cables I’ve bought from places like Monoprice or USBFever.com do work, but they just don’t have nearly the same level of click and polish. The default price is $25, but you can get it for as little as $15 on Amazon depending on the sale.
I’d also note that I think these retractable cables are plain superior to having a long Lightning cable in your bag. You save space, save any hassle of tangles, and the cables usually extend far enough for me to use wall chargers and laptop USB ports without any issue.