I've been sitting here on my couch for quite some time attempting to create an original flourish
That rather crosses the T doesn't it? Sitting around deliberately trying to force a specific outcome causes your inner critic to go completely nuts on any attempt at creativity.
Really, the best thing to do is to just jam. If I want to write a screenplay, I free write until something hits me as a good idea. If I want to write some new music, I noodle on my guitar until I come up with a melody or riff I like and build off of that. I don't just sit there and go, "I will now write a sprawling, chart-topping rock opera!" and then actually do it. If that were the case, I wouldn't be hanging out here. I would be going on a road trip through continental Europe with an entourage of Swedish groupies.
Stop worrying about the end result and just screw around. Inspiration is too ephemeral to really be forced, but if you're setting aside the time to just jam, it makes getting good ideas a lot easier. Getting into the groove is the fastest way to shut off your inner critic that does not involve achieving an altered state of consciousness. Hey, pot and LSD worked for The Beatles, but considering what happened to one of my favorite vocalists of all time, Layne Staley... well, there's a reason I'm not endorsing that particular route.