I think the best advice is never give up, because it's really easy to get dissapointed if you don't have the results you were waiting for and you need to be so patient. I am posting my comic since almost one month ago and I'm still with just one subscriber, which is so fine but, of course we all want to be succesfull and we all want to share our stories with many people.
Just be sure you enjoy what you do because at the end of the day, it will be your biggest motivation to carry on 