To make a pan reduction sauce, drain off nearly all of the fat from cooking leaving only enough to coat the pan. Return the pan to a medium-high flame (saute heat). Next, add your aromatics, toss once or twice, and then enough liquid to deglaze the pan -- preferably wine, spirits or stock. Then, finally build your sauce around the melted fond. The pan must be kept hot during the entire process, so reduction is fast and constant during the process. The sauce's structure comes from a combination of fond, reduction (hence the name) and ingredient choices -- a butter finish, cream, or tomato paste by way of a few examples.
To make a pan gravy, you drain off the fat, but leave just enough to create the right amount of roux. Again, add the aromatics over medium high heat, but this time let them take on some color. Add the flour, reduce the heat, and cook the flour until it reaches the desired color. Then add the liquids and other ingredients, bring to a boil (still over medium heat), and cook long enough for the flavors to marry.
Note that for either type of sauce, the bare minimum of fat from cooking is used. Note also, that in the first type of sauce -- fat is frequently added in the form of cream or butter.
If you want specific help with pan reductions, PM me your email address and I'll send you the first draft of a recipe designed to teach all the necessary techniques. If you want to talk more generally, let's start another thread.