I do have a provisional route and looking at it on a map, I will admit there are a few bits where I'm tempted to grab an extra tile if it's less than 50 yards off my route (especially if it only involves a left turn).
I generally didn't even look, since I had other things to consider. The ride has since actually become the backbone of my cluster spur to Sheffield north of Stratford-upon-Avon, but even if you ride without considering tiles, generally it's much easier to tick off a region two tiles wide than three.
However, in the Leeds region I had preexisting tiles, and it was fairly easy to thread my ride through the unticked gaps.
Avoiding spurs was probably my biggest concern there, I never like doing spurs, let alone on a tour.