1. In my internet research many people said you could use parchment paper to dehydrate your leather. That is a lie. Don't believe those people, they are not your friend.
2. My parents' dehydrator came with one fruit leather tray. The tray is really the best thing to use. I also tried to use nonstick lining paper. While it worked better than the parchment paper, it still didn't work as well as the tray that came with the dehydrator. If you want to do your own food storage and make your own healthy snacks I highly recommend buying your own fruit leather trays. I've provided a link below for your convenience.
3. Some dehydrators apparently have a temperature gauge as many places where I researched said to set your dehydrator for 140 degrees Fahrenheit. My parent's dehydrator does not have a temperature control. You just turn it on and let it to it's thing. So I would suggest checking your trays periodically and rotating them if necessary. My bottom tray was done right away and I feel like it got a little too dry in certain spots, while the upper trays still had wet spots.
4. Going along with evenness, try to spread out your puree as evenly as possible to avoid over drying certain spots. I smoothed mine out as evenly as I could, and your edges are still going to dry first, but you don't want to ruin half your leather while you wait for the other half to dry.
If you use these tips going forward, making fruit leather really isn't too hard. Making the puree itself was quick and easy. I used my ninja to blend everything together and then poured it on one tray at a time. The wait comes from letting the dehydrator do it's work, but in the end you get a tasty snack that you know doesn't have weird added preservatives in it! Happy fruit leather making!