What is the correct way to use the tip tinner?
The tip tinner should be used sparingly. My preference is to have just the very tip of the iron tip tinned. Gently press the tip into the tinner, submerging it only a few millimeters. Let it sit on your tip for several seconds, then wipe your tip off on a brass sponge. You should have a nice, shiny tip! You can also add a little tinner to your tip before you shut it down. That will ensure your tip is ready to go next time you want to solder. It will also help prolong the life of your tip.
What are the shape and measurements in millimeters of the ideal tip for through-hole soldering?
I prefer the conical tips for through-hole soldering. They provide a good contact on both the through-hole and the component. As for size, that is more of a personal preference. Typically, the smaller the components you’re working with, the skinnier you want your tip to be, but that’s not true in all cases.