Before you start: cold butter, frozen raspberries, and the freeze before baking, 20 minutes minimum and an hour if you have it, are the three things that decide how these come out. Photos and technique are in the post above.

1. Keep the butter cold. Warm butter melts on the counter instead of in the oven, and a scone made with it spreads flat. If your kitchen is warm, park the bowl in the fridge between steps.
2. Stop mixing while it still looks dry. A smooth, tidy scone dough has been worked too long and bakes tough. You want it shaggy and barely holding together when it goes onto the counter.
3. Frozen raspberries, not fresh. Fresh berries burst under the rolling pin and streak the dough pink. Frozen ones hold their shape and keep the dough cold. Do not thaw them.
4. Sprinkle the coarse sugar over the scones only. Any that lands on the parchment burns and smokes long before the scones are done.
5. Freeze the tray before it bakes. Twenty minutes minimum, an hour is better.
6. Full heat from the start. 425°F, plus 15 to 25 degrees if your oven bakes cool.
7. Go by temperature, not color alone. The tops brown before the middle is set. About 200°F in the middle means baked completely.
8. Two sheets, one inside the other. Keeps the bottoms from scorching.
9. Glaze only once they are fully cool, or it soaks in and disappears.
10. Salt. I use Morton kosher salt, and the amount above is measured for it.
11. Scaling. Changing the servings multiplies every amount straight across, and baking powder is the one that should not go up the whole way. Keep the first batch worth in full and add only three quarters of it for each extra batch: doubling 2 tsp gives 3 1/2 tsp, not 4.