Use room temperature butter for easier creaming and better texture. Chilling the dough is essential to prevent spreading and enhance flavor. Toast ground almonds lightly for more intense almond flavor. If jam is too runny, strain or reduce it to thicken. Press thumbprint gently to avoid cracking; patch cracks with dough if needed. Use a small cookie scoop for uniform cookies. Store cookies in a single layer to avoid smudging jam. Variations include different jams, nut alternatives, chocolate drizzle, gluten-free flour, vegan substitutions, and adding citrus zest.