Circuit board techniques
Toner transfer, Press-and-Peel(tm), photoresist, Sharpie, nail polish.
Ferric chloride vs. ammonium persulfate. How to dispose of etchant.
Commercial PCB fabrication. Vendors.
Dead bug style. Manhattan style. Veroboard. Perfboard and point-to-point. Solderless protoboard.
How to use a soldering iron. What is flux for.
Hot air soldering.
Hobby replacements for commercial reflow: skillet soldering, toaster-oven soldering, soldering using an oil lamp or candle.
How to fix mistakes: solder braid, solder sucker.
How to deal with fine pitch SMT devices.
How to deal with big, heatsucking components.