Most executive assistants underperform in their first few weeks for one reason: nobody told them how you actually work. They're guessing at your email style, your scheduling rules, and what you consider urgent. The fix isn't hiring a better EA. It's briefing the one you have. A solid preferences document takes about two hours to create and can cut the EA ramp-up period from months to days.
What Should Go in Your EA Preferences Document?
A preferences document is exactly what it sounds like: a written record of how you like things done. It's not a job description. It's the context your EA needs to make good decisions without asking you every five minutes.
The best preferences documents cover four areas: email, calendar and scheduling, communication style, and priorities. You don't need to write a novel. A clear, organized two to three page document is enough to get a new EA operating at 80% effectiveness within the first week.
Here's what to include in each section:
- Email: tone preferences, who gets same-day replies, what to archive without reading, how to handle cold outreach
- Calendar: protected time blocks, meeting length defaults, who can book directly, travel buffer rules
- Communication: how you prefer to receive updates, your response time expectations, when to interrupt vs. batch
- Priorities: your current top three goals, the relationships that matter most, and what you're trying to avoid spending time on
If you use an AI tool like River Executive Assistant, some of this context gets captured automatically over time. But even then, a written briefing document speeds things up considerably and reduces errors in the early weeks.
How to Brief Your Executive Assistant on Email
Email is where most EA relationships either click or break down. If your EA doesn't understand your email preferences, they'll either over-triage (flagging everything) or under-triage (letting important messages sit). Neither is useful.
Start by walking your EA through a live inbox session. Show them a week's worth of email and narrate your decisions out loud. "This person gets a same-day reply. This newsletter goes straight to archive. Cold pitches like this one get a polite no." Thirty minutes of narrated triage teaches more than any written document.
Then write it down. Your email briefing should cover your tone defaults (formal or casual, depending on the recipient), your reply time expectations by contact type, and any recurring senders that need special handling. Be specific. "Reply warmly to investors" is vague. "Reply to Sarah Chen within two hours, always copy me" is actionable.
According to research from Harvard Business Review, professionals spend an average of 28% of their workday on email. A well-briefed EA can reclaim a significant chunk of that time by handling routine correspondence, filtering noise, and drafting replies that only need a quick review before sending.
How to Set Calendar and Scheduling Preferences
Calendar management is the other area where vague instructions cause the most friction. Your EA needs to know not just when you're available, but how you think about your time.
Give them your scheduling rules in writing. Which days are for deep work? What's the maximum number of meetings you'll take in a day? How much buffer do you need between calls? Do you prefer morning or afternoon for external meetings? These aren't preferences your EA can guess from a calendar view.
Also be explicit about who has scheduling authority. Some contacts should be able to book directly. Others need to go through your EA first. A short list of names with notes ("book anything for Marcus, always check with me before confirming board calls") saves a lot of back-and-forth.
River Executive Assistant handles calendar context natively, learning your scheduling patterns and flagging conflicts before they happen. But the underlying preferences still need to come from you. No tool, human or AI, can infer that you need Fridays clear for strategic thinking unless you say so.
Communication Style and Priorities
The last section of your preferences document covers how you want to work with your EA day to day. This is often the most overlooked part, and it's where a lot of EA relationships quietly fail.
Tell your EA how you prefer to receive updates. Do you want a daily briefing at 8am or a quick Slack message when something needs attention? Do you prefer bullet points or full sentences? Should they flag everything or only escalate when something requires a decision from you?
Also share your current priorities. An EA who knows your top three goals for the quarter can make better judgment calls about what deserves your attention. They can filter inbound requests, protect your time for high-priority work, and proactively surface relevant information.
According to a guide from ProAssisting, the most effective executives treat their EA briefing document as a living reference, updating it quarterly as priorities shift. That cadence keeps the relationship calibrated without requiring constant check-ins.
Getting Started
You don't need a perfect document before your EA starts. A rough draft on day one beats a polished version two weeks in. Write what you know now, share it early, and refine it based on the questions your EA asks in the first few weeks. Those questions are usually a signal that something important is missing from the document.
If you're using River Executive Assistant, the preferences you set in the platform work alongside your written briefing document. The combination of structured context and AI-powered execution means your EA can handle more from day one, with fewer mistakes and less hand-holding from you. The goal is simple: less time explaining, more time getting things done.