Even better than 'so forth etc' get yourself a pair of glasses. Then when you need to pause, or if you want to impress the importance of your statement, remove the glasses and point with them to the person your talking to.
Also if you feel an 'ummmm' coming on, remove the glasses and chew on the arm lightly, pretending to be lost deep in thought. Stopping to polish the lenses also works.
If glasses arn't your thing, grow some facial hair and give it the odd stroke while answering questions. Metrosexual manscaping doesn't work here, but bizarre or unrully facial works best. People will instantly assume you are much smarter than your really are!
If I remember correctly a full Windsor looks a bit chunky on me and I'm more partial to a half-Windsor. I'll have a look on the Tubes and see what I can work out. Thanks.