When I was soldering, I realized that is difficult manipulate 3 things with 2 hands and that solder (one of them) only needs to be put at the front of the soldering iron, so I decided to make a simple solder dispenser mounted in the soldering iron that could be used with oly one finger, and this surged from there.
all you need is a soldering iron (of course) and a bike's brake's hose (I use it becouse I had it laying around and if you ant to buy it's cheap and also becouse it is metal inside, the tip is also metal and it's flexible and returns to it's original position to don't waste solder).
Step 1: Assembling
First hack the soldering iron.
Make a cut in the handle to pass the hose.
Then hack the hose.
Cut it in way that it can be glued in the up part and that the tip gets near the soldering iron's tip. The down part is cut in way that the tip is at the same lenght as the soldering iron and leaves a space between the two parts.
To mount it glue the top part with hot glue and the down with tape.
Step 2: How to Use
to use it just push the solder up and melt it with the soldering iron.