I want to write about the experience of dealing with art block at the professional level, because the advice designed for hobbyists doesn't always transfer.

Hobbyist art block: not feeling inspired. Solution: find inspiration, try a new technique, draw something different.

Professional art block with deadlines: cannot afford to wait for inspiration. The work must be produced regardless of creative state.

What I do: work on the least creative parts first. Flat coloring, background elements, any mechanical parts of the piece that can be done without creative investment. The act of working often unlocks the blocked creative state. Starting is the hard part; continuing is usually easier.

When that doesn't work: I work on studies. Value studies, color studies, gesture practice. These are legitimate billable activities in a sense — they maintain the skill — but more importantly they often break the block by removing the pressure of the specific piece temporarily.