I am about to harvest my key lime potted tree. I would like to cut a branch and start a new tree. Is it possible to do this and is there anything special I should do?

1-cut pencil thick branch
2- add rooting horemone to the bottom of the cutting
3- place the cuttting in pure sterile perlite
4- water and keep in a humid place ( cover by polythene bag to keep humidity)

Thank you.

You might be better off marcotting (air layering) a branch while on the tree. Better yet, plant seeds from your fruit. They will fruit in a couple years.
I don't have much luck with rooting cuttings, but marcotting is easy for me.