For Eastern Front WWII models being prepared for a winter campaign I can perceive three options:
(1) Paint the model white and add tracks, equipment, decals and so forth; base in winter snow
(2) Paint in summer colours and then use well-watered white paint to simulate a scrub with whitewash; base in winter snow
(3) Paint in summer colours and do the base in winter snow
The first is likely to look parade ground clean, the second will probably look realistically awful and the third does not represent any attempt to blend to the season. What, if anything, have painters tried and recommend ... or not recommend?
I dont cammo for Winter, Germans get used everywhere, and the Russians often go into later periods. Brits and US didn't do much with snow cam (No doubt there will be lots of comment on that un)
Summer base coat, then white overcoat (basically what the Germans did), then if you're feeling brave, stipple base colour where whitewash would have been worn away, doing a spray of mud up each flank above the tracks.
A warning against excessively white snow bases.
I did once, and redid the bases in a rather more muddy mixture afterwards
There's a danger of creating a dazzle effect that reduces the figures and models to an outline.
The best fix is to tone the white down with a tiny dab of brown.
Because snow doesn't remain pristine white forever.
Especially after armies have marched / ridden / driven over it.
And it isn't always viewed in direct sunlight.
My approach is similar to Steve's. I did Soviet tanks, but the approach applies as much for the Germans.
Paint tank in standard green, and shade and highlight. Then add 'whitewash' style camo relatively sparingly. For the bases I went with brown mud as the starting point, then painted some areas white, and added snow flock to these. I've found if you don't under paint the areas to be snow flocked the effect is rather underwhelming.
What I would caution with doing snow based and camouflaged units is that it does very much limit them to when they can be used. I do like to get as much usage out of my German troops as possible!
Many thanks for the input.
I guess carrying a personal summer field around with you is also a negative as is carrying a snow field!! Perhaps no basing at all. In practice I aim to paint my standard earth brown and lightly cover in white snow flock. The tricky bit is the whitewash: would a five-to-one water-to-paint mix create a suitable wash or will it just drip into the crevices? How do you get a whitewash effect on the more vertical plates?
For most basing I go with a mix of brown earth / mud and green flock - around 50:50. With the hope they can be used in most places!
For whitewashing tanks - I think I dry brushed / stippled it on - to avoid the pooling problem. But it was a while ago and can't really remember :-\