There are many tube quilting tutorials on the net, it is brilliant and so simple all the blocks come out perfect, very hard to explain you must watch the tutorial, one tip is to make sure your "tube' is pressed perfectly flat for good results.
I have made three Christmas table runners in no time using this method, I will be using this method for many more blocks as there is practically no waste of fabric.
I am giving a demonstration to my craft group next week.
Regards
Aussie Carol