Just move the telescope until the red dot is on the object of interest, then look through the eyepiece to view it. The RDF allows you to keep both eyes open while searching for the target, making it a lot more intuitive to use. I have personally purchased one of these for my telescope, and was able to find objects in seconds that it took me 10-15 minutes to locate with my finderscope. Now that we can find an object with our telescope, we have something usable to work with. If you want to enhance your viewing further, you may want to consider adding baffles to the inside of your telescope tube.
Baffles are washer-like rings that help to block stray light.
This has the effect of increasing contrast and preventing stray light and reflections from distorting the image seen in the eyepiece. If your telescope already has baffles, you will want to make sure they are properly placed. Perhaps the best way to determine this is to draw a rectangle on a sheet of paper that represents your telescope tube. It doesn't have to be actual size, but does need to be to scale. At the focuser end of the telescope, measure the diameter of the focuser hole and mark that diameter on one end of your drawing.