Well lets see:
First I have a scroll in my workspace (set to private) that I store all my ideas in for later use. That way I never lose them. If they are really good ideas, I create submissions with them (set to working) with some notes or poetic lines. That way, I have something tangible to get back to. It reminds me I should be doing this. (check my profile to see my working spaces)
As for the writing, I always force myself to write 10 lines of text (or edit 10 lines of text) every day. Most days I do more, but that is my minimum. Once you get used to the act of writing, writing becomes easier to do.
So I randomly choose something from my list OR choose a fun scroll or find something that interests me, and I do 5-10 lines worth of work on it. Then I might do some more on something else. However, I always spend some time doing it every day I am on the computer.
So you are probably going, but that is not finishing anything.
You will finish something... eventually. However, by taking it in chunks, you can tackle huge projects in managable pieces. Thus long submissions become obtainable.
The big thing about writing is the actual act of writing. Once you have it down, you can edit it to your heart's delight and search for perfection. However, if you don't have it down, you don't have anything. So 10 lines of notes every day, becomes 50 lines minimum in a week. A two hundred lines in a month. Since the average submissions has 50 to 100 lines, You can see how this eventually adds up. It adds up to submissions. Even if you are doing 8 things at once, eventually one will be done.
And 10 in 10 might be a good read for you http://www.strolen.com/content.php?node=2029