Car wax is NOT what you should be using. Read the contents of every wax before using it.
The silicone in car wax will cause all kinds of problems when it gets on your wood projects. Finishes and glue will not bond to the wood wherever there is any silicone on the wood. Fisheyes in the finish are the first visible indication of silicone contamination. I banned everything containing silicone from my shop almost 50 years ago because of this, and I burned up a lot of good wood that I had in the shop at the time. My car waxes and anything else containing silicone are now stored in my garage, about 200' away from my woodshop. Johnson's Paste Wax is what I have been using and I had bought a new can of it just before it was no longer on the store shelves (lucky me). The old can that I had bought about 30 years ago still has some left in it, so between what's left in the old one and the new one, I shouldn't ever need any more. What I have should last me longer than I'll be making sawdust. I'm 82 now. I've never had problems with the Johnson's Paste Wax getting on my projects and causing any finishing problems for me, so it's all that I'll use now.
There are other brands of paste wax that are similar in composition to the Johnson's Paste Wax. Butchers Wax is one of them. I think one made by Minwax might be OK too, but I haven't tried it. All are getting expensive, but buying a can is almost like buying a lifetime supply of it. For the applicator, I use about 1/2 of a washcloth, and leave it in the can so it stays moist, full of wax, and ready to use the next time. I wipe it on, let it dry to a haze, and then buff it off, usually with another clean wash cloth. The first time you should repeat this process, to fill the pores of the cast iron with wax. It will feel smoother with each use. In use on the tool surfaces it will wear off and when my project parts don't seem to slide easily I'll re-wax the surfaces again.
My scroll saw table get's waxed every time just before I begin using it. The table saw, maybe once a week. Others like drill presses, sanders, etc. usually get waxed when I think of it and whenever I've got the can of wax out to put on one of the other tools and realize that I haven't waxed these in a while. When new wax is applied, it softens and mixes with any wax still on the surface, so I've never had problems with too much wax. For the gears and ways of my table saw I apply this same wax, but thick, using an old toothbrush as the applicator, and I leave it thick. The wax stays in place well and it's surfaces dry to a crust, but stays soft inside, so it doesn't collect sawdust like petroleum lubricants do. Another problem solved by using Johnson's Paste Wax or similar.
Charley