Baking time: consider that all ovens and pans are different, even if they look similar. The baking time in my recipes is as accurate as possible, but it might take you more or less time. You can use a thermometer (like the OXO oven thermometer) to check that your oven is at the right temperature. I recommend keeping track of how your oven works and what tiny details you might need to adjust. 

Baking powder: it's essential for them to rise, so make sure it's not expired.

Very cold ingredients: I’m not kidding when I say very cold butter. I cut it and put the pieces in the freezer for 5 minutes before using it. And don’t take the cream half an hour before you start mixing the scones. Butter, cream, and milk belong in the fridge until you need to scatter and pour them.

Don't work the dough much. It should come together but still have floury patches. You don’t need to work it until it’s smooth, like pie dough, for instance. It is uneven, with dry spots sometimes, and that’s good for flakiness later.

A rather high oven: they need that extra heat (and baking powder) to rise however they can despite all that butter and cream. And if by any chance you forgot to turn the oven on before you start mixing, please don’t leave the baking sheet with the cut scones waiting on the counter. Put them in the fridge or freezer for the ten or fifteen minutes it takes for the oven to reach its temperature.

Freezing scones: cut them and put them on a baking sheet. Freeze until solid and transfer to a freezer-safe container or bag for two months (so you liberate the tray and have more space in the freezer). When ready to bake, take as many as you want and bake directly as instructed in the recipe card below. 

Citrus variation: add some lemon or orange zest to the dough before adding the liquid.