Keep the butter cold before incorporating it into the flour mixture.
Add extra buttermilk only as necessary to bring the dough together, taking care not to overmix.
Chilling the shaped scones in the freezer for 15 minutes helps them hold their structure in the oven.
Freshly brewed, strong coffee provides a more pronounced espresso character in the glaze.
Allow the scones to cool for a few minutes before glazing so the topping remains on the surface rather than melting completely.