They had several patterns for each season. The smocks were reversable too.
Here's a good link
http://www.1944militaria.com/waffen_ss_camouflage.htm
I don't know if a full scale lesson is what you need or want, but it's the only way I can explain what I have to say on the subject, so I appologize if it's too much, or unwanted info.
Check this link and examine the smocks pictured.
http://www.1944militaria.com/waffen_ss_camouflage.htm
Lets tackle the first pattern in the above link as an example of how I would go about painting it. I use Humbrol enamels so I'll be using the coresponding numbers for those colors. I don't know specific color/numbers for other products, so you'll have to bear with me on that. Also, you'll need either a very tiny spotter brush, or a slightly larger brush with a fine pont. I rarely use anything smaller than a 0 brush these days, though sometimes a really small brush is neccessary. I have a 15/0 that I use on occassion. I don't know how your eyes are, mine aren't what they used to be that's for sure. This can be tough on them, but not as bad as it may seem.
I would start with a base of 29 Dark Earth. Next comes the dominant color, in this case green. 101 Matt Mid Green looks good to me for this green. Start with some rather large splotches. Not too many. You want to section the uniform out and provide one large splotch per section. It's okay it the green splotches of two sections are close together. This does two things. First it helps to keep you from over doing it, and second, it helps to replicate the way the thing was sewn together, in sections in which the patterns don't always mesh at the seam. Next come two to three smaller splotches per area. Then comes the tiny dots and the fingers that stretch off of the larger splotches.
Now it's time for the secondary color, in this case black. No big spotches for black, infact the splotches aren't really splotches. They are more streaks with lots of fingers coming off of them to cover the blank background remaining (make sure to leave room for the secondary color stages). Paint them as such. Start with a few big ones and then add the smaller finger extensions where needed. Make sure to paint some of them over the green splotches. Follow up with some black dots over the remaining clear background color. Notice on the sleaves of this example that there are black splotches with background color dots and a black circle in the center of each. Just go back with the background color and add the dots, then add a smaller black dot, then add an even smaller background dot. You could add this pattern pretty much anywhere, but I would keep it to a minimum to make it unique.
The other patterns are painted pretty much the same way. Isolate and paint the base color first, then the primary color, then the secondary (and tertiary if there is one.) Start big and work down to small. Try to identify what makes a pattern unique too, and try to reflect it on your piece somewhere. Modern patterns don't really have a little quirk like that, but older patterns all seem to have one or two little aberations that don't appear anywhere else on the garment.
Hope that is of some use, and again, I'm sorry if it's too much. Good luck.