Take advantage of free breakfasts if your hotel, inn, or B&B offers them.
Many pubs serve lunches for less than £10; most restaurants offer cheap lunch or pretheater deals.
Make one meal a prepared sandwich from a bakery or sandwich shop.
Carry your own tap water.
In the larger cities, consider staying in a house or apartment.
Outside the cities, stay in a B&B or small guesthouse.
Check the websites of major chains for deals.
Ask about family tickets at major sights.
Spend time in the free national museums.
Check out sightseeing passes such as the Explorer Pass from Historic Scotland.
Use the exceptional public transportation system.