There are a few ways of making one-off pcbs, but I used the laser printer method. Hackaday actually has a really great tutorial for this here. On my first attempt I used parchment paper but it didn't come off cleanly when ironed onto the copper clad board. I ended up using magazine paper; it doesn't matter if it has print on it since only the laser toner is transferred onto the circuit board. With the iron I have, I had to press down for 5 minutes on each side for the toner to transfer cleanly. Next step was an HCL + H202 solution that etches away all remaining copper that isn't covered by the toner. My finished product wasn't perfect, so I tinned all the copper traces and checked with a multimeter to make sure all the connections were intact.
In my opinion, unless you need super low tolerances, the laser toner pcb etching method is a quick and easy solution for DIY projects.
(Pic is before tinning traces)