I do not use Neatsfoot Oil on leather. (There are some products called by that name, that have other things in it that are okay.) True Neatsfoot Oil was intended to be used on horses and cattle hoofs to prevent cracking. But those critters are growing live tissue. But on leather the stuff can cause the fibers to break down sooner or later!
I will use topgrain veg-tanned leather, which I do whatever tooling and then dye with Fiebing's alcohol-based leather dye, followed, when the dye dries by an application of Lexol Leather Conditiioner to prevent the leather from drying out. I will do the sewing, and then sand the main seam smooth on a rotary drum sander, followed by an application of Sole and Heal Edge Dressing. When almost dry the edge is hand-burnished using a deer antler tine, followed by hand rubbed with a plastic edgw wheel on the corners. Then I hand rub to finish it. For colors using black dye or combinations, I will apply Bag-Kote, which seals the color, but allows the leather to breath. I follow it all with an application of wax shoe polish. That's how I do it.