Excellent advice Dan
As for me, I never went to school or worked in a sign shop. I'm entirely self taught and learned by my mistakes, a far more expensive education in my opinion. Only because of my passion, desire and obsession to be as good as possible, I spent the past thirty six years striving to make every single sign better than the one that came before it. I read every possible book and magazine that I could get my hands on, tried every possible technique I could think of, and criticized every single sign I made in order to become the best I could be. I have never been satisfied that good is good enough, or that the customer is always right. I have no problem turning any client away that will not let me do my best work. It's my reputation on the line, not theirs.
Bottom line, you have to have at the very least, the basic fundamentals to begin with. Great design doesn't happen by accident. There is a knowledge base that is essential and without it, you won't get very far. School, books, an apprenticeship in a "good" working shop, are all ways to better your skill sets.
Ten years ago I offered and taught an accelerated sign making program. In one intensive forty hour week, my students would know more about how to run a successful sign operation than any of the local sign companies in my town who had been in the business for years. I stressed exceptional design, sound business principles, psychology as it applies to sales and people, software along with fabrication, tips and tricks. I literally fried my students brains but when the left here they had a thorough understanding of what running a real sign business involved.
Understand one thing...You can stay in this profession for the rest of you life and NEVER stop learning. I still haven't after nearly four decades.
And....Dan is right about quality. There are more clients out there than you can imagine who appreciate design and are willing to pay top dollar for it. The problem is a shortage of us in this industry who can provide that service.