I've never had a problem parking in Keswick, I just choose the back streets away from the town and park there. All of the free parking I use is from where cars turn off from the dual carriageway from Penrith all the way down to where the YHA building is, usually loads of choice. When I park I'm prepared to walk a bit to where I want to get to, for me its makes all the difference, cruising around and around just waiting for a 'magic' parking slot to appear is such a waste of ones time.
What happens so many times and I see it in Old Portsmouth so often, (we are a tourist area as well) is that loads of people desperately want to park next to a shop till, next to the coffee shop seat of their choice and next to the cinema front door and are prepared to sit in a long traffic jam coming into the city to try to achieve it. I'm sure they fail miserably everytime?
If I have to visit a local town or city, for example for me its usually Southampton, Winchester or Chichester I just throw my bike in the back of my car, find a parking slot on an outlying estate (loads available as most people have gone to work) and cycle to where I want to get to. When my son was young we would often go into a shopping centre, (rucksack and shoes on our backs) on our roller blades, easy to do as an adult when you have your child by your side. He's now thirty and neither of us do this now.