One of my colleagues recently put up a story on her door that can be summarized by the quote "Good decisions come from experience, and experience comes from bad decisions". I can certainly relate to that sentiment. I learned how to make most of the good decisions I make the hard way (and some from watching others make good/bad decisions). But the main reason I want to share this quote is because I think, among many things, it applies to doing research in economics. In particular, I can attest that "Doing good research comes from experience, and experience comes from doing bad research"; "Writing good papers comes from experience, and experience comes from writing bad papers"; and "Making good presentations comes from experience, and experience comes from making bad presentations."
A related sentiment that one of my MIT professors expressed when I was in grad school is that you have to give X bad presentations before you start giving good presentations and you have to write X bad papers before you start writing good papers (X was not specified; I suspect that it's a lot higher for me than it was for that professor). The moral of this is that you should start writing papers and presenting ASAP so you can make it through the bad ones and get to the good ones!