Breaking in leather shoes without blisters

New leather soles are slippery and new uppers are stiff. Both settle within a couple of weeks (sample guide).
Wear new shoes indoors for an evening or two with the socks you will wear outside. Then wear them for half a day, and rest them a day in between with cedar shoe trees inside.
If a heel rubs, a little leather balm on the inside of the counter softens it. If they still pinch after two weeks, bring them in: a cobbler can stretch a toe box by a few millimetres.