Lots of ways to skin the cat. Some use curves for their end row passes so lap two matches lap one around the outside. Some just hand steer and make AB while doing that so next time around they're good. You will ALWAYS have wide/narrow when switching from headland/curve to a straight line. Unless the headland is perfectly straight and in which case you just needed the straight line the whole time. 

Some hand steer that second lap to try and straighten out some of the bends. But for the most part, if you have section control....does it really matter? I told one guy that was so nervous about lining up next to his end rows to start in the middle of the field w/ his straight line. Then he has no choice but to fill in the straight rows and use section control on the edges.