It's not so much crazy things I do, as it is research being a habit for me - I do it even when I don't have any specific project in mind, or for projects that then never go anywhere.
I read an entire 600 page textbook on the history of Russia and researched Russian Orthodox prayers for a story that I then never wrote. I've also read a bunch of encyclopedias on organized crime (yes, there are several) for another story which I also never actually wrote.
In terms of visual research, I just collect all the things. I've got pictures of the eaves of temples in South Korea, just in case I ever have to draw a page in which I need to show a low-angled shot of a building with eaves that look like the eaves of temples in South Korea. For another comic, I've got multiple pictures of bloodstained fur - mainly wolves feeding on dead deer. I've got another folder full of nothing but pictures of food.
I've got an atlas of reproduced maps from 1665. I've got a badger skull on my bookshelf^, in case I ever have to draw a badger skull. I've got a series of illustrations going on in which I draw witches based on tea-flavours - and while drawing them, I drink the tea I'm drawing.
I'm very much a "just in case" kind of researcher - in the, "maybe knowing this will be useful some day, better read an entire book about shoes" kind of way.
^) I didn't buy it; I found it in the gutter outside of my house.
Having spent enough time on writers' forums for this to not even raise my eyebrows - unless the burning is an important part of the story, you're probably better off dissolving the body in a bathtub full of acid, and then getting rid of the resulting disgusting goop - if your setting allows for bathtubs and acid. I think the suggested chemical was either hydrochloric acid or lye, but it's been about a decade since I was in that particular discussion thread, so I could be mixing it up.
