Last weekend somebody asked me, "do you really do this much work before starting a campaign?"
My reply: oh, heck no!
What I have posted so far would be the work of a lazy afternoon. Over the span of 2 to 3 hours I would have scribbled out a map with pencil and paper and jotted down maybe a page or two of notes. I could have just shown you that, but would you have been able to make any sense out of "orcs" and "mind flayers" with an arrow pointing between them?
So I downloaded Hexographer and wrote up fairly detailed descriptions, or, at least, much more detailed than I would have written for just myself. If you've been at this for any period of time, you certainly have already developed a shorthand for describing places and monsters and situations your players are likely to encounter.
In Places Deep touches on this when discussing this picture of Gygax at the gaming table. You also see a lot of this in the Zak's Vornheim. We don't really need to be that detailed. Hex crawls are primarily powered by improvisation. What we've done so far is just give ourselves enough of a framework to build on as the players explore our island. We'll be hitting this point a lot. Most of the tools that we're going to develop are aids to improvisation. This includes the map I've been talking about for the past two weeks, the random encounter tables we’ll be tackling in the future and any other bits and bobs that invoke randomness (like random weather tables) or terrain details.
Unlike a West Marches game, classic hex crawls are not about going over the land with a fine-toothed comb. It's more on par with the Lewis and Clark expedition, exploring the terrain at a land-eating pace where one of the primary motivations is discovering what cool things the DM has hidden just beyond the horizon. The double-sided purpose of the map we have made is to both inspire and leave room for cool things to tantalize and dazzle our players with.