I notice fakes often have heavy edge wear. There is often discoloration along the edges, which is particularly visible on the back. Sometimes a thin white line appears along the edges because that's the true color of the paper, and it seems to pop out after the edges have been roughed up a bit. There are some terrible fake Leafs on eBay with lots of bids. Here's one of the worst:
https://www.ebay.com/itm/27480971758...MAAOSwstRgrDIO