I know this has been addressed here before but I am confused as to how one treats the door threshold. I can see how to trim out the door for a gasket around the sides and top but what do you do on the bottom? I don't want a lip that will become a knee breaker or a shin splitter if you know what I mean. I have a door gasket that is used on 18 wheeler trailer doors that I want to use but I still have to figure out the hinges. And if that doesn't work, I will go with the aluminum trim and foam gasket around the doors instead. But I don't see what the threshold will look like. Any suggestions or photos would help.