Frozen blueberries make the best muffins. Toss in flour to help them stick better in the muffins.
You can use a baking tester to check the muffins to see if they are done in the middle.
inspired by https://www.fortheloveofcooking.net/2010/12/banana-blueberry-and-lemon-muffins.html or the love of cooking @ blogspot.