Never Use Default Roads - Even When Using Default Roads

Inevitably, at some point during world creation, you'll start wondering if another road type would have looked better.  Default roads aren't easy to switch out, but custom ones are.  If you always use a custom road set - even if it mimics the default roads - you'll be prepared to experiment with existing roads later.

Along the same lines, it can be helpful to use a different custom road (even  if they initially match) for cities, rural areas, and in-between.  You might start out thinking they'll all be the same, but as areas develop a personality, road changes will likely become desirable.

If  you do need to change out parts of a road after lots and deco are placed, the easiest way is to delete and replace one section or intersection at a time.  This will make maintining your layoiut much easier.