Worst case scenario when working with your Thin Air Press vacuum bag is that you will get a hole or tear in the vinyl of your bag. While you can always fix a hole (video below), one of the best ways to prevent it from happening is to make sure the project you are pressing doesn't have any sharp edges or splinters.
Always be aware of material that could puncture the bag, on veneer sheets this is usually tiny splinters or sharp corners. Take a bit of time before pressing to sand these areas down and it will go a long way towards the longevity of your bag.
Check the edges of your veneer as well as they may have a sharp edge or splinters just waiting to tear your bag when you slide the project into it. Simply use a sharp utility knife and a ruler to cut the edge straight.
Jeremy from Boomstick Boards even showed us this great little tip where he actually cuts the corners of his veneer sheet on an angle before pressing.