In-line spinners & line twist;
Every cast with a Spinner will twist your line to some extent, the first thing you want to do, if you can is at the end of each retrieve let the spinner hang from your rod tip and let it “Untwist”. This will go a long way to keeping it from getting bad, but will not cure it. If you go with a swivel, make sure you use a good quality BALL BEARING swivel, I have done a lot of testing and Sampo is the way to go. Put it about a 1.5 ft above your spinner (no snap) and that will take care of just about all your line twist. For trout fishing I love Rooster-tails and most of the time do not use a swivel (unless trolling) and just work to keep the line twist to a minimum. When it starts and I am stream fishing I cut everything off and let the line run down stream without anything on it, let it unwind and then reel it in under pressure. This will remove the line twist most of the time. You can also do the same behind a moving boat.