She might have been talking about getting the knot down close to your work? When you tie a knot and it looks like it is going to too far from the work, before you pull it tight, insert the needle tip (tip not the eye)in the loop of the knot and pull on the thread tail as you slide the knot down tight to the work with the needle tip. Pull the needle tip out just before giving the knot a good tug to get it tight. Clear as mud right? It is hard to describe but easy to do.