Soldering is a handy skill to have (and an easy one to learn), but solder generally comes on a spool and isn’t terribly easy to dispense. To save yourself some trouble and make the whole process a bit easier, all you need is a non-mechanical ballpoint pen. (You also need a spool of solder, of course, but that should go without saying.)
Instructables user lucas_m came up with the idea to make a solder-dispensing pen to bring a little added convenience to the whole process. All you need to do is create a coil of solder around the the pen’s ink insert and place it inside the pen housing. Technically it’s a tiny bit more complicated than that, but not much, and you can check out the full Instructables guide for pictures and detailed instructions.
How to Make a Solder Pen [Instructables]