Going East or South
If you are heading East definately don't forget to stop at Dunnet Head, the most northerly point of both mainland Scotland and the island of Great Britain. From there you can visit John O'Groats and Duncansby Head (the most north easterly part of both mainland Scotland and the island of Great Britain), before taking a ferry to visit Orkney.
There are several ferry options;
Scrabster to Stromness | Northlink Ferries
Gills Bay to St Margaret's Hope | Pentland Ferries
John O'Groats to Burwick | JOG Ferries (foot passengers only)
East
South
