1. Have a clear scenario, with a clear objective - based on a defensive battle or mobile battle but not 'fair fight' - makes it very clear who wins or otherwise - the attacker must do 'x' (need not be actual objectives, could be something else) they win if they do it, otherwise the defender wins. Possibly with a rough sketch on planned terrain in advance so can bring something suitable, and perhaps provide a bonus to some of the oddball lists like mountaineers or even ski troops)
2. Work out the lists in advance suitable for the mission, potentially unbalanced forces (with the balance via the objective of the mission) - or a clear selection of lists to run
3. Total points allowance for either side, split into companies as desired (so some can be larger and some can be smaller, reduce 'padding' and make it easier to run several smaller companies)
4. Limit the types of companies to bring a mix in, so say no more than half the total companies in any of the four types (armoured, mech, infantry or fortified)
5. Use the full 'total war' rules (so you can pick a 'force type' for some additional bonus rules if desired, also provides a default scenario if not doing specific type of game under #1)
Also probably have a clear plan for how to handle players who may or may not be able to turn up, or are likely to arrive later (e.g. 'waves' of reserves, or forces that could be added to either side, say using 'captured' equipment if the game is going badly one way or the other)
Oh yes..
6. More such games! (even if only single day events) - open to suggestions, we have D-Day as a regular thing, have done Kursk (sort of), Market Garden. Thinking something around the fall of Berlin when the book comes out, though obviously slightly adjusted to allow the Western powers in on the act but allows Lee's Soviets (and mine
) out of the box. Or perhaps something in Italy?