One of the guys at Atlas Cases off Santa Fe handed me a plastic knife, like you get at a fast food place. He said that it is what they use and if you take your time, it does an really good job on the pick and pluck in a Pelican.

The other suggestion he made was not to cut the foam at all but to layer the foam in the case. Make sure that you have enough tension in the case with the foam to keep the contents from shifting. Like MarkCo is saying, you are trying to keep the contents from shifting. If you cut inserts in the foam, all you are doing is limiting what you can carry in the case to what you have cut out. Pelicans are too expensive to only put a few things in. Local travel in vehicles, I use soft cases. Air travel gets me to pull out the Pelicans.