TENTATIVE LISTS OF THINGS TO DO OR  AVOID

Tailor it to your possibilities. Easy, but you might be tempted to chew more than you can. 

Turns and average time length, compared to the expected game time you have (after all that waste with using both thumbs 200times  minutes on that little piece of Asian electronics).

Length of table, leave flank(s) space to avoid the forever end of the world and linear  fight. It is linked to the number of engaged troops, their probable formation and space use and the terrain density.

Depth can often be needed, but a bit of critical thinking might go further than " the  middle" as one side might want more of it. Otherwise you might have a defender depth deep and unused. On the other end check if the defender artillery are not limited in their firing, artificially as the attacker (or just one side) is starting too close. it might be a scenario feature though (fog?). Be sure that the side which needs to be able to reach the other side of the table, for example, has plenty of time to do so. Or if the scenario is that he has to rush, figure out how to still give a bit of leeway; you will underestimate it...

Linked to that: think well the positions of key terrain features compared to the table space. (even if historical fight, then the playing surface might be moved from the historical map). Terrains that are effectively closing part of the table? move all to have most of the closed up space out, no need to waste. (rivers, huge dense woods?)

Key defensive features that are likely to be used as such should no end up close to the table side (rear) as it will effectively curtail in an artificial way the defender (or likely user) rear maneuvering space. It might also provide unrealistic and even game sabotaging, security to those terrains.  (cf. my river game up).

Unless a very simple terrain, it pays off making a quick sketch on paper and thinking of what can happen. Once 95 tree bases, 27 hedges and 400 figure bases are set up it is too late. That is where being able to set up before people are coming to play is  best used. Internet and electronics can be used too, sketches can be crudely made on Paint, send to the players, or the relevant part of them for ideas and input. I think it could even be externalized, in that someone else not playing can do a lot on line, though I never yet tried to do that. I imagined a teams pregame umpiring exchange. You do it for my game, I do it for yours.

Most of us cannot afford an umpire. On the other hand if you are blessed with 4-6+ players one can be the director of terrain, set up, and umpire at the beginning. It is often at these stages he'd be most useful. He can start playing after a few turns as a subaltern commander. Possibly not knowing before hand on which side? or on the side which needs most fog of war etc.

 He can put unseen Fog of war terrain, numbers, speed up reconnaissance, check troops detections and introduce bits of role play and realistic unknown. Go to the essentials don't waste time on discussions. 

It might be often better to abstract pre game recon than get extended games turns spent on trying to find the other side. On the other hand it varies mush with period and subject. It can even be the game. 

Think well of victory conditions. In solo games it matters less, you can tweak. Card events tailored or not can go far and wide to focus things and create a sort of controlled chaos. You can even that way change one side victory conditions on the way, the other one knowing at the end or when  it looks obvious. A sort of Friedland from the beginning?