During the opening of the Bear Jew scene, the Basterds are removing the socks and boots of dead Nazis and tossing them about the forest area. Is there any reason for that past just further "humiliation"?
Quote from Tarantino himself:
Definitely. You took it right out of my mouth. Yes. I mean, basically what they’re doing - you described it really, really well. To put in even shorter nutshell, they’re actually doing literally the Apache resistance, but against the Nazis, against the Germans.
And that was one of the things - one of the reasons I wanted to do something like that, other than for all the other reasons you said before about - it’s a revenge fantasy and this and that. We’ve never seen it before. I was trying to do like a spaghetti western but using World War II iconography.
So in my re-imagining of this whole thing, I kind of placed the Jews as the Indians in this scenario. And that is part of the whole thing. You know, when they say they ambush a German patrol of six guys and then they scalp them, maybe even take their shoes off, so when they are found there is even less dignity in the death - all these little things that they do.
To summarize the rest of the article, the idea is to spread fear to the remaining Nazis, so they start fearing the Basterds. The Apache were so good at presenting themselves as a fearsome foe, that their enemies would sometimes commit suicide before they were even attacked, out of fear for what "the savages" would otherwise do to them.