My 5 pennuth!! If you go South , it is a different ball game to up North with regard to bank mooring. My advice would be to stick to the 24hr moorings , yacht stations and hostelries. Up North you can bank moor where safe to do so (remember trees have roots that protrude into the water) and certainly not on someone's prize lawn. There are Augusts and Augusts, some are very busy and some are not. Weekends tend to be busier than in the week. There are some fabulous moorings down South, I am sure there is a list somewhere , and they are all safe together with a list of yards and the facilities they offer, ie pump outs , water etc.
Mooring on Rhond anchors isnt a mystery and I am sure someone on here will give you some important pointers as to how to moor on Rhond anchors. The River Ant has some lovely informal moorings. How Hill has loads of moorings. St Bennett's Abbey has good moorings. As has been said sometimes it is purely the luck of the draw. You can pass a mooring and find it full up and if you had passed 5 minutes later there would have been space.
Finally, I will shut up in a moment, bring with you a 'just in case meal' if you intend to eat at pubs. Otherwise bring food for a few days and take it slowly.