I've been trying to compost for years. It wasn't until I took the course at the Soil Food Web School that I really understood the what and why of it.

The most important thing is maintaining aerobic conditions. If you see white ashy spots inside when turning, that means it went anaerobic. The white stuff is actinobacteria, which suppresses fungi in the soil. This usually happens when there's too much nitrogen and the bacteria population explodes, using up the oxygen faster than it can diffuse into the pile. Really high temperatures, like 165F+ is a sign that you need to turn the pile or jam a tool handle into it and make a chimney.

Using a cheap compost thermometer, recording daily temperature measurements in a spreadsheet, and graphing it over time gave me the feedback I needed to dramatically improve my piles.

Attached is data from my first pile this season. It's not heating up quick enough due to lack of nitrogen.