Its an odd thing passion, as ewe would often only associate it with art or maybe great Michelin star chefs and not necessarily butchers, but remember without the very best ingredients those Michelin star chefs wouldn't be able to create that masterpiece. The other thing maybe to remember is that doing a difficult, dirty, physically demanding job means (and being one of them I'm qualified to comment) that butchers need to be approached using kid gloves.
First tip if you want something out of the ordinary is, don't be a turkey customer. What is a turkey customer? - well, this is the person who uses their butcher once a year, walking into the butchers saying "can I order a turkey, the one I had last year was great." Clearly your butcher hasn't thought of or dealt with any other samples of meat since Christmas last year.
The turkey customer will get what they ask for, but throughout the year if you want something special, ask for well aged mutton leg or beef onglet for example (picture below) and make sure the turkey customer gets pushed to the back of the queue.