DRAWING A LITHOGRAPH
When I began making lithographs I wanted to learn how to etch and print for my own drawing habits rather than learn how to draw what would always readily print. Getting to the point where you can print whatever you draw requires a lot of patience and practice and means you will encounter some troubles along the way. But if you begin by making relatively simple drawings (in terms of what materials are used, rather than the complexity of the image itself) you will encounter very few troubles in processing and printing, making prints faithful to your original drawings in a short amount of time, I know that if you have ambitious projects in mind, starting simple doesn't appeal to you, but consider that this is a good idea to at least become familiar with the processing steps and how the press works; then when you move on to more complicated works you'll have solid knowledge of at least the basics.
Your first consideration is that all drawings print backwards from the way they appear on the plate or stone, reversed right to left like a mirror image. This is a crucial factor if you plan on using any lettering in your image (as the most obvious example) or if your images are very directional in composition: you may want to sketch them first and then reverse the sketch before you begin work on the plate to have a guide to work from. Portraits, as another example, have a way of looking incorrect unless the reversal from right to left is taken into account in advance. You may want to do your preliminary sketches on tracing paper so you can flip them over, or put your studies (face down) on a light table to work from. Eventually you won't have any trouble dealing with the reversal process and you won't be surprised by the results when you print, but in the beginning you might be irritated when you're trying to locate passages on your plate from your proofs.
If your preliminary drawing is highly detailed you may want to transfer key elements or patterns onto your plate or stone. A transfer sheet can best be made using tracing paper but a smooth grade of newsprint 'will also work. Pour a liberal amount of denatured alcohol onto this sheet and sprinkle powdered red iron oxide onto it; rub the pigment into the sheet as thoroughly as possible; when this dries you will have a piece of red iron oxide "carbon paper" to put under your drawing; make it large enough to cover your plate or stone. Place it face down with your drawing or sketch (also face down) on top so you can trace and transfer the key elements of the image. If your initial drawing is valuable and/or you can't see through it, you may want to make a version from it first on tracing paper. I know this involves a lot of work before you even begin on the plate, but you needn't go through this trouble unless your image calls for it. A ball point pen or sharp pencil works best for drawing over the image -- it will make a sharp reddish line on your plate. The iron oxide is easily distinguished from your drawing materials and will not attract any ink.
If your original sketches are not highly detailed then you can draw directly on the plate or stone with red conte crayon (which also does not attract ink) to map out where things go; again the color difference separates what will and will not take ink.
If you want, of course, you can just begin on your plate or stone directly with a light pencil sketch from a #5 or a prismacolor pencil; neither is likely to show immensely in your final print. some of the potential problems you need to be concerned with.
You may wind up thinking that there are too many rules for drawing or that they are much too inhibiting. If you find that the safe systematic approach is just too rigid for you - if you feel you have to wipe your drawing off the plate or stone with a dirty sponge and then draw back into the stain with a prismacolor pencil which you then smear around while you eat a cheeseburger over your image, then be prepared for these eventualities: (1) No one else will ever want to etch or even advise you on how to etch these images (2) You are going to be very surprised by what rolls-up. If you are open to change and accepting "accidents" or if this is your preferred way of working in other media and you want to try it lithographically, then you won't be disappointed. It is doubtful that you'll get an image anything like where the pigment of your drawing was last seen, but this doesn't mean you won't get something interesting. However, if you need every last crayon flick of your drawing to show in the final print exactly as you had planned it, stick with a conservative approach to drawing and etching.
From the Stone and Plate Lithography Lab Manual by Lise Drost, Greenwall Press, 1992