I am brand new to napoleonics and 10mm. Does anyone have a guide to painting mainly white uniforms that looks good?

Welcome....Austrians arent easy, I'd suggest using a good quality acrillyic and a light undercoat although I last did them with black undercoat. You may use a slightly darker colour for the cross straps so offwhite maybe.

Experiment !!!!

The Austrian infantry uniform really wasn't white at all but undyed wool, called perlgrau, or pearl grey.  When in barracks there was a daily cleaning regime that required the soldier to whiten his uniform with chalk and brush it.  On campaign it would not have been easy to keep it clean and it would have got have dirty very quickly.
I haven't painted Austrians but I have painted Dutch and plenty of Spanish for a Peninsular project, both of which wore white uniforms made from similar material and the first thing to say is don't use white paint. 
I usually undercoat in white, because it reveals blemishes better than black, and if you thin the top coat slightly, the highlights show through.  With white subjects, though, I use Vallejo Neutral Gray 70.992.  I then use an off white for the top coat, such as Vallejo Off-White 70.820, and when the figure is finished and properly dry I give it a wash with Vallejo Sepia 73-200, diluted 50/50 with water.  When that is dry I highlight with off-white and then pick-out things like straps with the same.
Limit the use of white generally, it is too stark and white clothing and equipment wouldn't stay white for very long anway.  The same goes for black.  Use Vallejo Black-grey 70.862 rather than pure black.

Leather brown, sepia wash, leather brown highlights, dun highlights, then Vallejo ivory

I undercoat white, basecoat in pale grey and then highlight in white

This is my painting instruction table for Austrian (German) Fusiliers:

UNDERCOAT WHITE
212   Dark Grey   (Officer – coat)
211   Light Grey   Coat, breeches (Officer – collar, cuffs)
FACING   FACING   Collar, cuffs, turnbacks (Drummer – swallow-nests)
219   Chestnut Brown   Flesh, musket, canteen (Drummer – drum) (Officer – sash)
529   Beige Brown   Backpack
231   Mid Grey   Greatcoat
212   Dark Grey   Helmet, pouch, scabbard, gaiters
524   Tan Earth   Base
      
211   Light Grey   Crest, belt, straps (Drummer – hoops)
VGC 007   Yellow   Crest (Drummer – hoops)
219   Chestnut Brown   Helmet plate (Officer – crest) Ensign – finial)
504   Panzer Grey   Musket-barrel, bayonet
(Drummer – diagonal hoop-stripes, sticks) (Officer – sword) (Ensign – staff)
      
HIGHLIGHTS
214   Flesh   Flesh
101   White   Coat, breeches, belts, straps
525   Uniform Grey   Helmet, pouch, scabbard, gaiters (Officer – coat)
VGC 057   Bright Bronze   Helmet-plate, scabbard-fittings, musket-lock (Drummer – drum) (Ensign – finial)
VGC 055   Polished Gold   (Officer – sash, crest)
VGC 052   Silver   Musket-barrel, bayonet (Officer – sword)
504   Panzer Grey   Crest-centre, helmet-peak
      
BLACK INK WASH
101   White   Belts, straps

That's the order I paint and the colours used - all Coat d'Arms paints and washes unless noted as VGC Vallejo (obviously facing colour varies with regiment).

And looks like this in 10mm


Austrian Fusiliers Regiment - IR 56 Colloredo by Zippee Jerred, on Flickr

Quote from: Zippee on 31 May 2023, 10:23:56 AMThis is my painting instruction table for Austrian (German) Fusiliers.....

Well, that seems to work.  One thing, the woodwork on Austrian muskets was blackened.

I know John, but painting the musket black just "looks wrong" to me.

Its just one of a myriad of inaccuracies but that one is at least deliberate.

All figure painting is impressionistic - if it looks right it's good.

Disagree entirely.  We might as well just have a univesal figure for everything, one generic tank and one generic gun.  No thanks.  Infinite variety is what keeps me interested, and has done for the last half century.

Quote from: John Cook on 01 June 2023, 12:41:30 AMDisagree entirely.  We might as well just have a univesal figure for everything, one generic tank and one generic gun.  No thanks.  Infinite variety is what keeps me interested, and has done for the last half century.

Same here...my goodness, it really is almost exactly a half century!

As long as everyone playing knows what the thing is I don't care if it's right.

Nice to have the right model nicely painted but far from essential IMHO.

Well, it isn't mandatory.  I suppose it depends whether the game is all that matters or not.  There was a bit of a moan on here recently about the Confederation troops for the Peninsular range being without plumes and that they wouldn't be suitable for the 5th Coaltion 1809 range, so detail is importan to some people.  I don't get deliberately painting Austrian musket brown, when they were black but I doubt it would gate anybody drummed out of the Brownies.  For me the game is almost secondary.  I get immense pleasure from research, collecting books, prints and other documents, I even have a large collection of period drill regulations (I know).  I could pursue the research aspect of the hobby and paint moidels without even gaming I think.     

One of the many things I find fascinating about this hobby is the infinite variety of ways people find to enjoy it

Quote from: John Cook on 01 June 2023, 02:18:48 AMWell, it isn't mandatory.  I suppose it depends whether the game is all that matters or not.  There was a bit of a moan on here recently about the Confederation troops for the Peninsular range being without plumes and that they wouldn't be suitable for the 5th Coaltion 1809 range, so detail is importan to some people.  I don't get deliberately painting Austrian musket brown, when they were black but I doubt it would gate anybody drummed out of the Brownies.  For me the game is almost secondary.  I get immense pleasure from research, collecting books, prints and other documents, I even have a large collection of period drill regulations (I know).  I could pursue the research aspect of the hobby and paint moidels without even gaming I think.     

you'll be taken with the irony that I am the same person commenting on the Rhinebund plumes as painting muskets brown - to be honest at this scale at playing distance the brown is so dark its not noticeably brown, just dark. Black* however is too stark and "looks wrong", dark grey is worse. That's my viewpoint, and I'm happy with the look, which frankly is all that really matters these days. 

All my 'black' is actually panzer grey anyway