For individual tiropita, cut filo in half on the long side and then butter each piece, one at a time, fold in each long end slightly and butter again, then add a tablespoon of the feta mixture to the top and fold into a triangle by bringing one edge to the other side and then again until its all folded up. Butter generously on both sides and lay on a sheet tray lined with parchment paper and then cover with plastic wrap and freeze for later use or bake immediately at 350 degrees Fahrenheit for 30 minutes, or until lightly golden brown. If baking from frozen, bake at same temperature for about 35 minutes, or until lightly golden brown.