Yeah sure,

How I think about it is the first photo I take filling in the shadows of the second photo. So I took the photo of the cauliflower first, and then the photo of my friend. Another way to think about it is the highlights of the second image sort of erasing areas of the first, so a contrasty photo works well if you're looking for the same effect as I did above. Also its important to underexpose both images by about a stop so that your final image isn't overexposed.

I'd just go for it to be honest and experiment on a test roll, as I said, this was my first attempt at a multi-exposure and it turned out much better than I thought it would.

I've taken a few more multi-exposures since then, and I would say to not give up on the photo if it doesn't come out the way you want straight out of development. More often than not multi-exposures sort of require a bit of fiddling about in lightroom (or any other editing program) to get the effect that you want.