This is an article that I'm writing for me, but I'm using the second person “you” to make myself feel better. Just so you know. If you find this useful as well, great!
Okay, listen up. You need to actually get things out there. You need to really finish things. So here's what you're going to do:
Go to an online retailer of the thing you are trying to make. In my case, that's books. So go to some online bookstore. Don't bother with the best sellers, not right now. Right now go down the list a few pages, to the people who are all clearly self-publishing.
Find someone whose book you just can. not. Stand. Revel in how much you hate this book, in how much better you are at writing than this person. Then remind yourself of the following fact:
As of right now, this minute, that person is winning. Their book is up for sale, and people have purchased it. Yours is still in your head or in some rough draft form, and people have not. You are “losing” to that person because they have accomplished your dream, and you haven't yet. You know you are better than them. You know you “deserve” to have your book out in the world where people can see it more than they do, you know your book is better than theirs.
Okay, this is an ugly side of yourself, and you'll never reveal it to anyone else. It's understandable that you're a little ashamed of yourself for thinking this way about a fellow practitioner of your craft. But now it's time to take that shame, that anger, and that (self-)righteous indignation that they are “winning” and you are “losing” and turn it into motivation. Yes, your book still has that one chapter that isn't quite right, and that one section that could use some fine tuning. But look at their book! Their book is all weak parts! And they are selling it! People are reading it and posting positive comments about it! Don't worry about taking on the giants of your craft yet, that will come with time. For now set your sights on getting your book higher up the sales charts than that book. By getting it on the sales charts in the first place.
And when your book starts selling, when you finally get onto the list, quietly buy a copy or two of that book, as silent recompense for using that author as the scapegoat you needed to goad you into action. Put all those negative emotions behind you, they are unworthy of you. You've taken this step. Now you can take the next.