Keeping scope honest
Scope creep rarely arrives as a big request. It arrives as "while you're in there, could you just…". One small favour is good service. Ten small favours a month is unpaid work and an unclear contract. When something new comes up, reply warmly and specifically: "Happy to help with the newsletter. It's outside our current package, so I'll send a quick quote for it today." Clients respect this far more than they resent it.
Keep a simple change log in the client's shared folder. When a task is added permanently, update the scope in writing and adjust the package price.
Your own security habits
Use a separate browser profile for each client, lock your screen when you leave the desk, keep your operating system updated and turn on full-disk encryption. Don't work on client accounts over open café Wi-Fi without a trusted connection. If you ever suspect a breach, tell the client the same day; how you handle a mistake matters more than the mistake.
Offboarding cleanly
Every client relationship ends eventually. Keep an access log listing each account, the type of access and the date it was granted. At the end, hand over any documents and SOPs, ask the client to remove your delegation and vault access, confirm in writing that it's done, and delete local copies of their data. A tidy exit is often what earns the referral.