There is another solution if you're determined to clad your calves in leather. George at KG shoes (253 Eversholt Street, London, NW1 1BA, 020 7387 2234, firstname.lastname@example.org) can work wonders on too-wide and too-slim boots. He says that if you can do the zip up, then walk for a few minutes in the boots, that may stretch the leather. However, if they're much too tight take them to him and he can stretch them by at least an inch using a heated boot-stretcher (yes really!), but this works best if the lining is also leather. Boot stretching costs a reasonable £15.00.
If baggy boots are the problem, George can also sort this out although it involves major surgery and so prices start at £75. The process involves fitting the boot to your calf by taking the top section apart, taking in the back seam and reconstructing it, all totally invisibly. Your boots should be in safe hands, KG's clients include numerous Bond Street shops, design houses and department stores.