Like Munz, I use a spot meter for LF, and use it to determine the proper exposure based on the shadows. - This for B&W. When shooting MF, I am more often shooting colour film, and then my whole procedure is different (and because I am new to Colour, evolving). For colour, I am shooting transparancy film, which has a smaller range than I have with B&W. If the scene has a lot of contrast, then I use the spot meter to meter for highlights and accept that I will lose detail in the shadows. If the scene doesn't have too much contrast, I generally just do an incident light measurement and get exposure that way.