I would say it took me about a year to get to the stage where I can FMQ any shape and size I like. I've heard it equated to learning to write. I would recommend practice sandwiches of around FQ size, you want to be able to get hold of them and have room to manoeuver. Like Sandy, I made up some table runners as soon as I thought I was getting a little better. I've never marked as I think it's harder (for me) to follow a drawn line than go freehand. I'd say the two key ingredients to success are self-belief and practice! Oh, and a glass of wine before you start helps to relax those shoulders!