Well, even after you turn pro you should still continue to learn and grow–it really is a life-long journey. I doubt any masters when dying of old age felt like they had mastered it all, and for most creative types, a lifetime is not nearly enough to do all that we want to do.
Important stages of growth don’t necessarily happen before one made a living as an artist. Whether you make money with your talent/skill is not really a watermark in your artistic journey–plenty of people who make a living as artists are very limited in their skill and even their level of talent–to the point of being dubbed as incompetent or a hack, yet they can still enjoy a career doing it. Which industry you become a pro in does make a difference though–for example, if you want to be a concept artist for film and games, then the accepted skill/talent level would generally be higher than some of the other industries. There’s also style and intent. An artist who does abstract or very simple cute greeting card illustration may not have the goal of mastering photorealism, and it would be unreasonable to expect that from such an artist. So one question every aspiring artist needs to answer for himself is “What career path do I want to take?”
For me, I got serious about drawing around 13 or 14, and I knew I wanted to be a storyteller first and foremost, and my artwork is there to serve my storytelling. That has never changed, and I’m always happier illustrating my own intellectual property than playing with someone else’s toys. Well, fan art can be a lot of fun I guess, since you’re emotionally attached to works you are a big fan of.
My sketchbooks were typically filled with anatomy studies, life drawing (of family and friends and classmates), storyboards, concept art…etc. As I got older, my sketchbook became more like project planning/research, where I’d design stuff for an upcoming painting, or working out a problematic composition I’m dealing with on a new painting, or concept art for my screenplays and treatments. I’d still practice some of the other stuff, but not nearly as much. My growth at the later stages were mostly project based. For example, if I was working on a painting that had an infant in it, I’d do research into what makes infants look the way they do, and I’d do sketches to figure out the core qualities of an infant’s proportions, skin tone…etc.
One of the most important aspect of practicing and studying smart is to not merely copy, but read between the lines and understand what are the core ideas in a lesson. This is precisely why the most useful tutorials aren’t necessarily ones where the artist just documents all the steps–the best tutorials are the ones where the artist explains the ideas and philosophies behind his working method. He’ll explain why he chose a particular composition, why he used a particular color scheme, or why he lit the scene a certain way to achieve a particular mood, or why he prefers to draw female noses a certain way.
When practicing–let’s say a life drawing of your girlfriend sitting on the couch playing your Xbox360. Assuming she’s not naked, you’d have to draw the folds in her clothing. Instead of merely copying what you see, you should take note of where the compression points are, how the wrinkles will go from the compression points to the stress points (for example, the armpit is a compression point, and the shoulder is a stress point). When you understand the core ideas behind how and why nature works the way it does, you’re well on your way to learning and practicing in a smart manner instead of just going through the motions and spinning your wheel.
The most drastic improvement phase for me happened during the time when Craig Mullins was still active on the internet (at Sijun Forums). Many of the members there didn’t go to a high profile art school like he did, and he was very nurturing to us pups. He taught us the core ideas behind why things look the way they do, the higher concepts of visual construction and structure, such as the relationship between textures and values and colors, how form and colors contribute to an image and which is more important, and also taught us how to deconstruct an image and figure out why it can convey the mood or style that it does. I had already been a professional artist for about 10 years before I wandered into the Sijun forums, and of course I had some idea of all that stuff, but many links were missing and some concepts were hazy in my mind. It wasn’t until being part of the Sijun community and learning from Craig did everything eventually come into focus. He spelled it out in ways I had never thought of before. It’s a shame he’s no longer active. I miss him like hell. Craig essentially influenced a large portion of the current generation of young concept/matte artists.
In any lesson about visual art, you should always remember that the core ideas are always the same, and they are the most importan and also the most basic foundations in any image. I personally break it down into something like:
Depending on subject matter:
-Design (biological, mechanical, architectural, decorative pattens/colors…etc)
Depending on medium/style:
Depending on intent:
-Idea behind the image (storytelling, atmosphere, socio-political statement, emotional expression, intellectual exploration…etc)
To answer your other questions, I didn’t discover Loomis until I’d already turned pro, and most of the stuff he taught I’d had already picked up from other sources (Jack Hamm, for example) or through experience. What I did find more helpful to me at that stage was Creative Illustration, as that is the most advanced book of his IMO. It deals with the higher concepts like those Craig taught us at Sijun.
The whole planes thing is really about helping you understand how to simplify the complex curved surfaces that exist all around us. A good analogy is if you took a color photo and ran it through Photoshop’s “posterize” filter, and you’ll see how it simplifies millions of colors into just a handful, but retains the overall color scheme. Visualizing complex curves in planes is just like that, except it deals with shapes instead of color. To be able to draw in planes effectively, you must first do some time in perspective lessons, to at least understand how basic perspective is constructed, otherwise you’d struggle with drawing in planes.
For drawing, I didn’t start using the computer/tablet until about 1998, and by 2001 I pretty much converted to digital for everything except personal enjoyment (I love traditional oil painting). Prior to 1998 it was all traditional mediums. Is doesn’t matter what you use though–just please don’t use a mouse.