What I keep forgetting about timeouts

If a config file has more than a dozen options, half of them aren't being used. The other half are being used in ways the original author didn't predict.

I keep a small log of decisions in a text file. Not architectural — just small ones. "Picked X over Y because Z." Future me reads it more than I thought he would.

The fastest debugging trick I've learned is to write out, in one sentence, what the system is supposed to be doing. Half the time I notice the bug while writing the sentence.