When I shoot with the camera sitting on the ground, I often need to place something under the front to tilt it up just a few degrees. I end up using whatever I have in my pocket - credit cards, business cards, a pen, etc...

What do you use? I thought of a simple wooden wedge, but is there something better?

Pretty much the same deal. Whatever I have on me, or whatever is around. Sometimes take off my grip vest, roll it up, and use it, (started doing that when I first saw the CineSaddle back in the 90's and thought, "that's COOL, but I'll be DAMNED if I'm paying that much for one of those.)