Well, making gravy with ground beef is a little tricky, so you have to enhance it a bit with some kind of beef boulion or French dip powder (ok in a pinch), but what I usually do, is when I have a roast beef, I always make a little extra gravy and freeze it......much nicer tasting.
After you brown your beef, remove it from the pan, drain the pan leaving just the bits that have cooked to the bottom. I add a tablespoon or two of olive oil and turn the heat high (ish). Sprinkle in a tablespoon and a bit of flour and cook it into the oil. When it's sizzling and browning, add water and whisk it to make it smooth. Start with smaller amounts of water....maybe 3/4 of a cup to start. (it's easier to make it a little thinner, than to thicken it back up) Season, or add a little boulion at this point, to taste.