Most brand projects get stuck on the logo, ship the logo, and call it a brand. Then someone who wasn't in the room has to use it, a new hire, a freelancer, the next agency, and the whole thing quietly comes apart.
Start past the logo
A mark with no system behind it falls apart the moment someone else touches it. The real work starts with positioning: what you want to be the obvious pick for, and who you're willing to not be for. Only then do you move to the mark, the type, the color, and the voice that carry it.
Document for the person who wasn't there
The test of a brand system is whether someone can extend it without calling you. That means a living guidelines doc that covers usage, spacing, and the 'please don't' cases, enough that staying consistent doesn't depend on the memory of whoever designed it.
Build it that way and the rebrand looks finished on day one and still looks like itself two years and three hires later.