One task per session
Start a new session for each separate job, so one job's leftovers don't end up steering, or being paid for by, the next.
The whole conversation goes back on every request, wrong turns included. Three old jobs are three jobs you are still paying to re-read, and three sets of assumptions still in the room. Anything worth keeping goes in a file first.
Say it to your agent
“One job in this session: fix the login redirect. When it is merged, write what you learned to docs/progress.md. I will run /clear before the next job, so put anything I would need in that file.”