The number one benefit is a smoother, more satisfying keypress. There will be less scratchiness in the action and you’ll get much better sounds. The same is true with stabilizers — your spacebar and modifiers will feel smoother, have a more consistent feel, and will be quieter with less rattle.
Once the switches are open, you’ll want to apply lube to the rails on the sides of the stems and the correlating rails on the bottom housings and around the circle on the bottom and the small tube on the inside of the stems. If the switches are linear, you’ll want to apply some on the legs where they make contact with the metal leaf.
To start, you’ll want to take them apart, separating the wire from the housings and stems. Next, apply lube to the inside of the housings and to the outside of the stems. Cover the ends of the wire in dielectric grease, extending it past the curve of the wire so the clip is lubricated. Finally, reassemble the stabilizers and test them in your keyboard, adding more lube if they feel scratchy or more grease if they still rattle.
If you aren’t satisfied with just using lube and grease, there are countless other ways to mod stabilizers. The most common are:
Holee Mods (aka Band-Aid mods) and clipping, which can reduce rattle and make cherry stabilizers feel more responsive, film modding, which is similar to the Band-Aid mod, and wire balancing (shown at 5:40), which can reduce rattle and make the keypress more consistent across the key.
After the stabilizers and switches are finished, put the board together and try typing on it to make sure everything feels right to you. If your board has to be soldered, DO NOT solder anything yet.
Remove and adjust any switches or stabilizers that seem off or unsatisfactory. Once you’ve checked everything, the board should be ready for final assembly and use.