Update mangoleather.md

docs/files/recipes/mangoleather.md

@@ -95,6 +95,8 @@ Using a silicon mold: 7 days (or until it comes undone)
 
 **Post-processing**
 
+Trim frayed edges and cut or slice into desired shape before the slab is completely dry and hardened for best results. 
+
 Store in a dry and ventilated room.
 
 **Further research needed on drying/curing/growth?**