Camping & Bothies
Scotland's prime camping season spans between April and October at most commercial campgrounds, where you expect to pay around £20 for two for a basic site. Many of these are primarily RV and caravan parks and part of the Camping and Caravanning Club.
If you're tenting you might find these a little overbuilt, so you'll need to choose your campground carefully. It's also worth noting that many rural hostels allow camping.
Scottish Camping is a useful and well-run website with extensive campground listings and plenty of user reviews.
Wild Camping
But if you're self-sufficient then the options are incredible since Scotland’s liberal access laws allow wild camping in any open country. Outdoor Access Scotland sums this up: