After 6 months of DE shaving, I would like to pass on one extremely valuable and simple piece of advice to the new DE shaver:
Choke up on the handle. By this, I mean grip the razor around halfway up the handle, or thereabouts, when you shave. Sometimes I actually grip it closer to 3/4 of the way up. I believe that this is why the merkur HD handle is so short to begin with; there is simply no need for a long handle. Other razors may be similar by design.
I usually balance the bottom of the razor handle on my thumb, and use my forefinger and or second finger to hold the top of the razor; the thumb will serve as a fulcrum of sorts, helping you to balance and manipulate the angle very easily. This will allow you to control the angle of the razor MUCH easier and more effectively versus grabbing the handle near the bottom, like one would usually do with a disposable, Mach, etc.
For me, I find that the proper angle to hold the handle is actually closer to parallel with the ground instead of perpendicular to the ground.
I wish I would have known this when I first started; it would have saved me a lot of time and minor discomfort!
Just thought I'd pass it on.