My preferred method of committing design to block is to simply draw on the block. I do this either with sumi ink and a brush or with a "magic" permanent marker, depending on the design. Sumi-ink drawings are more fluid and resemble more Chinese or Japanese designs while permanent marker drawings can be more detailed and "Western" looking.
Working out compositional details with pencil first eliminates the fear of committing drawing to ink. Pencil or charcoal on block can be erased easily. Two cautions: heavy application of graphite can leave a greasy film that will not accept marker or ink later, and too much pressure applied with a sharp pencil on soft wood will leave an indentation that may show on light printing.
One drawback with the direct draw method is that the design will be reversed in printing, but with some years of practice it seems I have learned to "flip on my head" and end up drawing exactly a flipped version of what I really wanted.
Once the drawing is finished, it can be transferred to the block by flipping the paper over the block and using either carbon paper or charcoal rubbing.
In the case of tracing paper, the drawing can simply be pasted down on the block with rice paste and the carving proceeds right through the paper.
One of my favorite types of carbon paper is a red paper sold at http://www.imcclains.com/ that is soft and transfers even the slightest line. I am also the proud owner of a stack of about 400 sheets of old typing carbon paper picked up on eBay for about $2.98. Pressing down too hard when transferring with carbon paper can leave a dent in soft wood blocks.
For transfers which are drawn (or photographs) and printed from a computer, the method I have been using most is printing on a plastic substrate such as transparency film. This is the stuff that was used in overhead projector presentations before the advent of MS PowerPoint.
I use laser transparency film and print on an ink-jet printer. The ink-jet ink remains wet and much care is needed not to drop it on the way from the printer to the studio, since it will invariably fall on its "face" (like the proverbial buttered toast) and will make a mess out of both the transparency and the floor. Not that that's ever happened to me.
In any case, the procedure is simply to work out the drawing or photo on the computer, print on the transparency, place the transparency face down on the block carefully and apply hand pressure to transfer the ink. Excellent detail can be achieved with this method.
Moving right along, this year I'm in an experimenting mood and I acquired some "Studio Paper" a wax coated paper, also from McClain's and a few sheets of iron-on transfer for ink-jets from my nearest office supply store. The last method, and the one I use most often now, is the traditional hanshita from Japan; I purchase prepared paper from the Baren Mall http://www.barenforum.org/ but it is easy enough to make my own.
The illustrated story of those last three methods in the next post, the dreaded sequel: Methods of transfering design to block Part Deux.