I must admit to being rather envious of people who can teach themselves a creative or technical skill just by watching YouTube videos. The sheer amount of online 'academies' out there now, make it seem like everyone is doing it. For the past few months I have trying to do just that with art and graphic design. I have to admit, however, that I have been struggling with distance learning in addition to having a job. It can be so joyless sometimes when you're not getting the results you want.
Adobe software is expensive and after fumbling around with a free trial and a Lynda.com account, I eventually capitulated and went for a classroom-based course instead. Now that I've gained confidence in class the tutorials on Lynda.com and SVS click so much more than they used to. All the Illustrators I admire are working digitally, or are using a mixture of traditional mediums and digital tools. It really is essential to get these skills, but don't do what I did and beat yourself up because you're not getting it straight away. Working with these programs is not as intuitive as everyone likes to pretend it is.
Using classroom based courses as well as online tutorials may not be the cheapest way of gaining technical skill but it is probably the quickest if you choose (and are lucky enough to have the time and money to do) intensive courses. If you have the chance to go on intensive accredited courses, I really recommend it. I had to swallow my pride and admit I wasn't progressing using just online tutorials. If you're going to do something; do it right.