These are just ordinary crepe paper strip/foam strip roses done on a smaller scale with straws. Cheap because you can get a whole box for a dollar or just accumulate them from the fast food place a month or so in advance. The softer (cheaper) and longer the straw, the better it works. Don't use bendy straws, though.
Insert the scissors into the straw, cut one end of your straw about 2 inches.
Open up the cut
Start at one corner of the open flap, roll diagonally
Keep rolling all the way up to the end of the cut.
Keep rolling, the end of the cut will create a little bump, this forms the bud/center of the rose.
The angle of the roll will make the straw rise above the top of the rose. When this happens, fold the straw under and keep on a-rollin'
Rol,l roll, roll, fold, roll some more
Until the end of the straw
End of straw sticking out
Fold the end under till it overlaps the stem
Tape the end with some tape (masking, floral, electrical or just magic tape) and wrap the stem in a downward spiral. Color with a magic marker if you're using masking.
I did a pretty crappy job on this one, but you get the picture.
I shouldn't have used a clear straw, since it made photographing much harder, but it's the only kind I have on hand.