Wvdek, I use the tube method. I like that the "cuff" of the pillowcase is basically lined, making for a more finished look. If I don't have anything for the narrow contrast strip, I just leave that off and still use the tube method.
I just set it all up like an assembly line; and for me, it's just as easy to make a dozen as it is to make one.
Thanks everyone for the kind words.