Mike, Jackster gives some good advice. Here is some more. Stretching will not help reduce tangling if line twist is the cause, and it appears to be in your case. You must remove the twist, that's the only cure. Here are a couple more ways to do that..
Bruce

Line twist, cause and cure

Many casters cast with a slightly (or not so slightly) elliptical casting stroke. This will cause considerable line twist. Always roll casting from the same side will also twist lines badly. Everyone twists lines to one degree or another, here?s how to fix it.

Pull 6-7 ft. of line from the reel and hold the line in a big U shape with the upper legs of the U about 6? apart. If the line is twisted the U will twist around itself. Pinch one leg of the U between thumb and forefinger. Twist the line with your fingers, if the twist gets worse, reverse twist direction. Now that you know which way the line is twisted, start casting and continue twisting the line between the fingers. This motion will work the twist out of the line and out through the rod guides. Repeat this process whenever twist returns, and it will.

Another method that works well is to swing the line in a circular motion with the rod over your head. With 20-30 ft. of fly line out of the rod, swing it in a clockwise circle over your head, if you are right handed, counterclockwise if your are left handed. This will twist the line in the opposite direction that your casting twisted it and also cure the problem.