Too much liquid in the batter will lead to scones that are tough and dry, so it's crucial to prevent fruit from mashing and leaking excess liquid into the batter.
Avoid using overly juicy or overripe fruit and make sure to rinse, drain, and dry your fruit well. If you're using frozen fruit, it can be added directly into the batter.
Fold the fruit into your batter with a spatula to avoid mashing any of the fruit and its liquids. You can even toss your fruit in a light dusting of flour beforehand.
If your recipe calls for puréeing a portion of fresh fruit, check the consistency of your batter and alter your liquid to dry ingredient ratio so your scones stay nice and tender.