PCB making

For smaller pcbs Osh Park is cheap, with three pcbs for a total order cost of $5 per square inch, with free shipping.
Minimum size is 1/2" x 1/2", which costs $5 x 1/2 x 1/2 = $1.25 total for three pcbs including shipping.
 
For a prototype you can use dry film. It works as a negative (the removal traces should be black on the print)
The development process uses a sodium carbonate solution and the final removal of the mask it uses caustic soda
But I seldom use it. Lot of a mess with chemicals
I usually order from jlcpcb. You can order 2+ sides that can simplify the drawing process and includes solder mask and silkscreen. The only drawback is the customs and postage costs