The terror of the blank screen

Dog walking, so much easier than startingMother's Day (36 hours in Scotland cooking and dog walking) – tick.  Desk tidied – tick.   Head on electric toothbrush changed – tick.  
Nothing, it seems, stands between me and starting time slip number 2.  Except the terror of the blank screen. I've even found myself hoping for revisions to drop into my inbox so that I can put off starting a little longer, which I may very well come to regret.  Be careful what you wish for!

I have an idea, and I even have a working title (The Memory of Midnight) and I know that all I have to do is to start a rough draft.  I need to rattle off scenes without worrying about how to link them together, without caring about punctuation or even making sense, without thinking much at all.  Because at the end of it, I'm just going to throw it away and start again.  I might retain a glimmer of an idea, or a snatch of conversation, but that will be about it. 
It's frustrating, as it feels like such a waste of time, but it appears to be a vital part of the process for me.  After 60 books, I know this.  So I should just get on with it, right?  Instead I'm thinking about doing a story board, as suggested by the wonderful Blake Snyder in Save the Cat! 
I'm thinking that rather than sit here and start typing, I'll pop along to Staples and buy some blank cards and carefully write out scene locations and character view points and what changes in the scene.  Then, the theory goes, I'll pin them to my board and plot out the story arc, making sure I can tick off (more ticking off, my favourite thing) set up, catalyst, debate, fun and games, 'all is lost' and all the other points my story needs to hit.  Then I will have a perfect plan that I just need to follow.  I'll give myself a timetable, and set off and in a month or two, the job will be done.  Easy.
I wish, wish, wish I could write like this.  I tried it with Time's Echo, and successfully wasted a lot of time setting out a board that I never looked at again.  I blame the fact that a time slip has two parallel stories and it got far too complicated making them both fit the arc, but the truth is, I suspect that I'm just not a plotter. 
So I should just flex my fingers and start writing something, anything.  And I will, just as soon as I've run through every other justification for not plunging right in.  I could do character descriptions, I could research.  I could brainstorm motivations and goals. 
Or - I know! - I could read books on how to write.  I've still got Robert McKee's Story and Christopher Vogler's The Writer's Journey to study.  Why didn't I think of that before? They've been sitting there on my shelf for months, but whenever I've picked them up before, I decide they look too hard to get to grips with, and I put them back.  Excellent. I'll get them down right now.  That's at least a day before I have to square up to the blank screen again.  Phew.    
How do you get going on a new story or project?  Do you faff around like me, or just plunge in?  All tips welcome!