Gerard de Marigny
The best advice I would offer is the advice I heeded when starting out just three years ago. That is ...
+ learn your craft, write your works, edit your works, publish your works, let others know you've published them ... then rinse & repeat!
+ Don't spend too much time or money on marketing and social media. Word of mouth is the best device to sell books. Word of mouth comes from having a breadth of quality published works. So write better and write more!
+ Don't be defensive or thin-skinned. Be a professional, which sometimes means to be courteous in the face of negativity.
+ Believe in yourself!
+ Trust in yourself, but first make yourself trustworthy ... do the work!
+ Persistence ... tenacity ... relentlessness ... discipline! You only fail if you quit!