To be taken for what it is - ramblings of a weirdo. A weirdo with a heart of gold, and good intentions.
Look for Inspiration Outside of Your Medium
One of the biggest mistakes I see is people only gathering inspiration from art made out of their own medium. Admiring your fellow -insert artist type here- is fine of course, but make sure to mix in a slew of other sources as well. This will help keep your art unique and fresh and help you steer away from trends.
My personal inspiration tends to come from digital and oil painters, fashion photographers, movies and my favorite: people watching.
Don't Blame Your Equipment, or Lack there Of
This has to be one of my biggest pet peeves. The artist that blames their equipment or the fact they don't have what they "need". "If I just had -this- then I would be sooo much better! ...But I don't so oh well". I can not stand this line of thought. It's pure poison. Rotting the m