Get a hotel in the suburbs or next town over to save money
Shack up in Bristol instead of Bath, Leith instead of Edinburgh.
Not every major British city has a secondary city of significant interest in its own right that's close enough for this to work (London being the obvious one—though you could always try a suburb), but some do.
This option is a bit of a triple-edged sword, if such a metaphor is possible. It is almost always cheaper to stay in a smaller satellite or nearby city than it is to stay in the major/popular one, especially during high season.
However, even though you are saving money, you are stuck staying in somewhere other than the big city you came to see, plus you've got to factor in the price of the train you take every day for that 20-minute ride into the big city (always stick to some place within a 30-minute train ride of the big city).
Even so, you do get a chance this way to experience two cities, one smaller and far less touristed than the main one, which only enriches your overall experience.
This option is not for everyone, certainly not if it's your visit to the major city and/or you have only a limited time to see it, but it can be a welcome option if the main city is booked solid in high season or during some trade fair.
Also in Top 12 hotel savings:
- Check the hotel website
- Avoid breakfast
- Share bathrooms
- Share a room
- Try a bidding site
- Pay cash
- Sleep for free
- Consider alternative accommodations
- A warning about user reviews