Just sideways, with the top of the skull facing outward. That's the way those tank crews had it. Still an unfortunate insignia which probably saw more than a couple of them shot by angered Allied soldiers who believed they had an SS man before them. In my hometown even a couple of fire brigade men were shot by approaching US GIs who did not believe that German firemen wore soldier helmets and black uniforms. After the Battle of the Bulge and the Waffen SS atrocities in Malmedy as well as after the liberation of the concentration camps (mostly not guarded by Waffen-SS, but by Allgemeine SS, but those differences got lost), Allied temper with SS men was short.
That doesn't make every SS soldier a war criminal and every Wehrmacht one a saint. The Wehrmacht had its ample shares of atrocities and all too often looked the other way where POWs or the population of occupied countries would have needed their protection from the SS and other Nazi murder squads. Not every SS soldier was a volunteer (by the later war years people were drafted into the Waffen-SS) and the Waffen-SS also attracted attention as giving a quicker career as an officer (even if you were not an academic and not of blue blood), higher pay, more modern weapons, an international "Foreign Legion type flair" (half its members were non-German) and a generally "cooler image". But Waffen-SS units also had higher losses, such high losses that in Wehrmacht circles the saying was "the Waffen SS is great to use in battle - but only once ..." as the ranks of Waffen-SS units were often depleted after battle to an extent where you had to rebuild them from scratch. And the Waffen SS certainly had a higher share of particularly mean and intolerable warcrimes even at a point in time when the war had not turned as nasty as in 1944/45. The first Waffen-SS atrocities were as early as 1939 (Poland, with an official Wehrmacht report complaining about "needless cruelty") and 1940 (France, shooting of Brit POWs on a field way behind the front by young SS men with Hitler Youth background who must have been in a frenzy). Waffen-SS soldiers tended to be younger than Wehrmacht ones and consequently more reckless and indoctrinated as they knew little else than the Third Reich and its lies.
Waffen-SS membership is still something that raises an eyebrow in Gerrmany today. I was only recently in the house of an old lady who had her late husband in full uniform regalia as a framed picture on the wall, circa 1942/43, and underneath the glass a small dried flower obscured his lapel badge where the telltale SS-runes would have been. Of course, the black lapel on his otherwise suitably Wehrmacht-looking uniform still gave him away to the knowing eye. I also knew that he had been a member of the Leibstandarte Adolf Hitler and that that fact was always "not talked about" in his very catholic family.
