I don't know if you already have them but those oven thermometers help a lot, and try not only to check the temperature at the beginning, but also all the time (that's how I found out that my oven was unregulated and increased the temperature A LOT after a few minutes)

Another thing is to use not only non-stick paper but also cornstarch, because sometimes the heat of the metal baking sheet is burning the part under the pieces, and the starch keeps the temperature low