just go along the coast , slowly and have an adventure .
some things some folk think are interesting might not interest you. so go on have fun find the places that do.
plan nothing and have a good drive.
There are some wonderful places inland as well. Lots of Lochs, large and small, waterfalls etc. The NC500 is a very popular route and well worth doing, but it is very busy, well worth doing but just following that you would miss out on so much more beautiful scenery.
we have done a lot of it already before it was popularised by magazines and tv! now its a nightmare, still might do it next year on the scoot, camp somewhere central, do it in bits? biggest problem is the weather and the wee beasties! somebody did ask about doing it on another forum towing their car on a trailer, they were shouted down!