mmm i beg to differ. i'm a fulltime freelance artist myself for the past 8 years now, and i do commercial illustrations too in order to survive. and in paintings, i still need to judge the look and feel, the overall mood of the picture, what would suit the situation best. the actions and reactions of people in the picture if any, what would someone do, if placed in that situation, that scenario, at that point in time. what kind of clothes they wear, what kind of accessories. is it night? is it day? is there music playing in the background? is it windy? is it cloudy? the colors of everything, does it go together? do i want something to stand out? there's still a lot of these little things, colleges will never be able to teach you, and regardless of fine art or commercial art, it will still be applied. these are the things u need to build on. ultimately, its the same whether you learn design, illustration, web ... your design sense plays a pivotal role. and on a personal level, i like to google random images, listening to music that suits the mood of the painting, to inspire me to paint. of course, this doesnt mean i take my own time to do this, in commercial work, time is always of essence. u'll need to able to judge and act and start sketching out ideas within a few minutes. but one step at a time. again, its all about the art and design sense that you build up. the more you understand, the faster you can work.
digital or tradional, it makes no difference really. its just a medium. of course, there's many more shortcuts in digital granted, but i always thought it better if someone learns the long way and knows how to do it manually first. to me, its just about understanding how to do it. even up to today, while i know quite a lot about photoshop, i try not to resort to filters to achieve some effect, simply because of one thing ... it WILL look more rigid and fake, as opposed to painting it. the quality, the identity of the painting is an important factor to me, as an artist, and in such, i practice a same style of painting either in fine art or commercial art.
3dassets made a good point tho about knowing file types and compression. if your work is to be printed, know how big the final print will be, because you will need to adjust the size and resolution of your digital paintings accordingly.
of course, its all dependant on what you plan to do in the future. generally digital artists nowadays end up doing comics or concept art, occasionally matte paintings, for only that few various industries. not to say there's no other jobs, but these are the most common. in either of these, there's really not much need to know about intricate processes of printing. its good to know, even i read books and learn from printers about how things are done. but there usually will be other people thats going to handle these processes for you in the end