Scott:
Our standard draft angle ranges from 5 to 7 degrees. We use 7 the most. If a part has a fairly deep, narrow cavity (deeper than it is wide) we may go to 10 to prevent sticking. The draft angles don't really vary with the part size.
Fillets & corner radii vary a lot more. Our standard here is to have .094" corners and .125" fillets, but .063" for both is also fairly common. Some of our smaller parts have corners as small as .031" where necessary (clevis legs, for instance, or the flats on a hydraulic fitting) but this is best kept to shallow features where the stress concentrations in the die aren't going to be a huge problem, or where a thin rib leaves room only for that.
Fillets are usually more critical because they become corners in the die, which metal must flow around. Picture a rib standing from a flat part, with fillets at the base. As the dies close, metal flows around these fillets into the rib. If the fillet is too sharp, it won't quite make the corner, but will leave a gap, and as the rib fills, the metal may turn back on itself, leaving a crack at the rib base. Yuck.
Tougher material also calls for larger radii, because it flows less readily.
This has not been the most orderly post, unfortunately, but I hope I have answered your questions.
Cordially yours: Gerard Pawlowski Lakeview Forge Co.
P.S. Cliff: True enough that we have some good alloys nowadays. Unfortunately they aren't always easy to get, but that wasn't my point, really. I have on my desk a forged brake part that has been cut in half and etched to bring out the grain patterns, which follow the part's contour quite closely. With a hogged-out part, you can't get this; the grain follows the original block. This isn't so good for fatigue resistance. Of course the parts were probably heinously overdesigned to begin with, if they are government parts...