If using an oven, preheat it to 200℉.
Prepare fruit. Wash fruit that needs it and peel, pit, or core those that contain skin, pits, or cores. If you are dealing with a harder fruit, roughly chop it and soften it by simmering it in a pot on the stove.
Add fruit to a blender and blend until smooth.
Taste and add sweetener if needed.
Prepare dehydrator trays or baking sheets with parchment paper. Cut the parchment paper to size.
Pour the puree onto the paper and use the back of a spoon or spatula to spread it evenly to between a ⅛-¼ inch thickness.
If using a dehydrator, place the trays in at 135° for around 6-10 hours. If using an oven, place them in for around 4-8 hours. For either option, check your fruit leather after 4 hours and every 1-2 hours after until dry. When they have lost their initial shine, aren't wet, and a gentle press doesn't leave an imprint, then they are done.
Allow them to cool completely at room temperature.
Use shears to cut the fruit leather and attached parchment paper into strips. lay them flat or roll them up into a storage container, jar, or sealed bag. You can store them in the fridge or freezer.