I've been using a 10" liquidator for the past week or two, its a great squeegee but I was having problems with drag marks but fixed it with the angle of my hand but I'm still getting a few lines as I turn my squeegee, as I fan it's along the top of the turn one single line, with a new blade its OK for a few windows but then creeps in, I know it must be me as the videos I've watched are fine but I'm wondering how else to gix it please??