I'm a short-time reader and even shorter-time poster in this forum. However, I guess I can still toss out a few tips.
Personally, I do everything from start to finish digitally. I start with a blank file in photoshop, do my sketch in photoshop, then color/shade/texture from there. Now that I have been doing this for while, I can truthfully say that I feel this is probably not the best way to do things. I think the fine control that the friction between a pencil and paper provides really can help the quality of a sketch. I still find doing my sketches on the computer to be very difficult and lacking in precision. My sketches usually are not pretty at all. I make them presentable by coloring them.
Why do I do things the way I do? Sketching isn't my strong point anyway. I'm a much better colorist. I think I use my sketches only as a set of guidelines. I really define the form of whatever I'm working on in the shading process. I treat my coloring/shading/texturing more like painting than I do just coloring. By the time I'm done, the sketch is 100% obscured. And, if you peel back the layers... often half of it ends up getting erased from behind the color layers in the end. I am also rather lazy. A strong part of my motivation is probably based on not having to clean off space on a table, not having to hook up my scanner, and not having to remember what I did with the pencil sharpener.
Software wise, I primarily work in Photoshop CS2. Photoshop is unfortunately notoriously expensive. They do have a free trial, but it is the variety of free trial that really prevents you from actually using the program in any way that you would want to. There is also a stripped down version of Photoshop called Photoshop Elements that is less than 1/6 the cost. A lot of the functionality you would lose is stuff you wouldn't touch anyway. Photoshop is a very... robust piece of software. The other program I really want to add to my arsenal is Corel Painter (unfortunately, also not cheap - but it does have a stripped down version too... also called Elements!). The full version of painter is about 2/3 the cost of Photoshop. If you want something that isn't priced in the triple-digits, I would personally recommend Paint Shop Pro (also by Corel). As the name would suggest, Painter is designed around digitally mimicking conventional media. Paint Shop Pro is targetting more at photo editing. I would put it on the level of Photoshop Elements.
The other thing I use, which makes a world of difference, is a wacom tablet. Using it is about a billion times easier than drawing with a mouse, I find. I've been working on one of Wacom's graphire tablets for years, but I am looking to upgrade to an Intuos as soon as I can. (As they say, bigger is always better!) Really, I do find that the graphire (the lowest-end of Wacom's tablets) is quite sufficient. I really just want a new toy.
