Rebuild the missing context
Assume the recipient will not remember every date, promise, or earlier conversation. For a message about how to thank a coworker for covering your shift, use this factual base: name what the person did, when it mattered, and the practical or emotional difference it made.
Say what needs to happen next
State the decision, information, or practical action you need and include a real deadline only when one exists. Thank them directly and share one honest outcome they helped make possible. Make the immediate next step clear enough that the recipient can answer without reconstructing the entire history.
Avoid making urgency into pressure
Do not exaggerate, create a public spotlight without consent, or attach a new favor to the same message. Protect private health, financial, workplace, and family information when describing their help. Do not make the other person responsible for reducing the discomfort that prompted you to write.