As a writer, what is your best advice for the publishing process?

The most important thing to consider to ensure that your work gets published and bought is to have it thoroughly proofread, revised (where necessary) and reviewed (by professional/respectable critiques).

There are a couple of thinhs that are a must-do before approaching a publisher (it is dependant on what you write). Self-confidence, absolute familiarity with the craft and its market,,,,,,,,,,,,,,,,,,and a good agent!