For Galo, the answer is to be smarter about making money. Taking two gathering professions, buy bigger bags as soon as possible and focus on getting an epic flying mount to gather even faster. I think he may have some cash flow regrets.
If I had to do it all over again, I would probably have not changed tradeskill professions 4 times. I also would have started tanking sooner as a feral Druid than before. I wasn't a fan of tanking, but got asked to do it as a Druid. Now I enjoy it greatly. And I would have used voice chat more often. Things go a lot smoother on voice, even for the times that I can only listen (playing the game is one thing, being on the "phone" at the same time is another with the significant other.)
What about you? What would you do different if you knew what you know now.