I use the Travis method myself, before that I used a nice little pair of surgical scissors. They worked fine but were a bit tedious to use, and I did not like having to put the scissors inside the egg to make the cut, also hard to avoid cutting veins (which is not much of a problem for a full term snake). Now I use a big old pair of scissors. I open them wide and rest them flat on the surface of the egg, I begin at one end and start my cut, once I get a bit of the egg pinched in the scissors I can slit the egg open from end to end in a single stroke, I cut the absolute smallest sliver possible and often don't damage any veins, I get a great view inside and have never had a problem. I incubate at 88.5 degrees and slit at 55 days (an easy way to figure out 55 days from being laid is go forward 2 month and then back up 5 days, made my head hurt otherwise). one big tip on choosing the right pair of scissors for this method is to have THIN blades, it makes getting a starting bite on the egg much easier.