Learn by crafting and taking apart one thing over and over. It feels kind of silly, but sometimes it’s the only option, and it might actually be faster than reading books at higher skill levels:
Disassemble consoles and stoves for electronic bits, scavenge a giant pile of batteries (a number of recipes and dis-assemblies require soldering iron charges), and then craft and disassemble things at or near your current skill level.
Hacking scrap metal (smash a car if you need some) into antennas will get you to 1 or 2.
Taking apart and putting together a flashlight is enough to get you to 3, at which point you’ll have unlocked plenty of recipes to get you to 6.
Above 6 is harder, since the recipes take longer, use more charges, and have more rare ingredients.