Walking Tour: Salalah is a small city in terms of tourism. As most of the places are close to each other, you can explore some parts of Salalah on foot.
By Bus: there are daily buses operate between Omani cities, and these are very cheap as compared to taxies or hired car.
By Car: For most of sights within Salalah, you can take a car on rental basis. For outside attractions you have to book a car in advance. A drive from Muscat to Salalah, this 5 hrs of journey can be a memorable experience.