Unlike some countries, we do not work to set percentages when tipping in Scotland and as such is unquantifiable.
However in dining establishments a 10%-15% tip is usually expected.
In general, Scottish service providers do not always expect a tip, however if your receive exemplary service it would be deemed polite for you to choose an appropriate figure to tip them.
Essentially it is whatever you are comfortable with and there is no obligation for tipping.
Golfers: Golf caddies expect a tip of at least £20 on top of their flat fee.