What are the effects of cable ties?

When you use the ties on the left channel, twist them to the right and when you use them on the right channel, twist them to the left. This preserves polarity and prevents smearing. At least that's what I noticed in my system.

As long as the cables are shielded, both audio & video, you can use cable ties all day long. Don't over tighten.

Indeed, most cables are shielded these days so there is no worry. Twisting them won't help if they are well shielded to begin with. Check to see with your cable manufacturer if you aren't sure about their shield quality.

Now if they aren't shielded, a rat's nest is the best solution, believe it or not. You certainly don't want to coil the slack up, nor twist tie them together in parallel.

Arthur