Never underestimate how long a simple fix can take when you're impatient.
Working on aperture blades under dim light was tough. Switched to a brighter desk lamp, and no more squinting. My repairs are faster now.
Start recycling every part you can, no excuses.
Had a classic camera with focus issues that needed precise alignment. Waiting for the special jig to arrive from a supplier overseas added three weeks to the job. Once it got here, the actual adjustment was quick, but the delay tested my patience. It's a reminder how much of this work is just waiting on parts.