I was just clearing my desk (actually, shuffling papers from one side to another) and noticed notes I had taken at a 'Relax About Writing' workshop attended a number of months ago that I had not Blogged about.
One exercise we did at the workshop which I thought was kind of "cool" (sorry, felt like using that word) and which I thought would we worth sharing with my readership was "freewriting". The exercise is to write non-stop for five minutes anything that comes to mind - there are to be no pauses and the pen is not to leave the paper. Upon completion, read what you have wrote, either then or some time later, and pick out "nuggets" worth thinking about and exploring further.
Try it. It is meant to be "a technique to explore ideas and clarify thoughts" and "useful when you are stuck or overwhelmed". Also, apparently a great release "for emotions and frustration", like Blogging might I add.
Note that your freewriting doesn't have to be five minutes. You could write for a shorter amount of time... or longer, or perhaps keep writing until you fill a page... or two.
As well as freewriting, another tip for writing is to step away from "notes to self" and write with a reader in mind. In doing so, there is need for better explanation and this is where holes in your ideas/thoughts come to light.
More tips: keep a writing journal, carry a notebook, or even, start a Blog!