How do I prepare my leadership team to run the agency without me for a year?

If buyers see I can step out for a year, my valuation goes up

Hand each leader genuine ownership and authority, build the decision-making rhythms and reporting that replace your day-to-day involvement, move your relationships and new business onto the team, then actually step out in stages and fix whatever breaks. The 'gone for a year' test is the same as the value-creation test: the more truly it's passed, the more the business is worth.

The Long Answer

You've connected the two things correctly: the work that lets you disappear for a year is exactly the work that lifts the valuation, because both are really the same thing, a business that doesn't depend on you. Start by handing your leadership team real ownership, not just responsibility. Each person owns a domain (a function, a P&L, a set of major clients) with the authority to make the decisions that domain requires, including ones you'd have made differently.

Build the machinery that replaces you: a leadership team that meets as a genuine decision-making body, reporting rhythms so information flows and accountability holds without you chasing it, a board or chair for the biggest calls, and documented processes so knowledge isn't trapped in your head. Move the things that currently run through you personally, key client relationships, new business, the final say on everything, onto named owners over time. Then test it for real, because theoretical delegation isn't worth anything to a buyer. Take a proper break. Then a longer one. Ideally, well before any sale process, genuinely step out for weeks and then longer and watch what breaks. What breaks is gold: it shows you the hidden dependencies you didn't know you had, so you can engineer them out while there's time. Fix them, step out again, and repeat until the place genuinely hums without you.

A founder who can say 'I was largely out for the last year and the numbers held' is selling a fundamentally different, far more valuable asset than one who's never tested it, and crucially, even if you never sell, you've bought yourself freedom either way.