Cut the piece in rectangle shape, the width of the piece depends on the tube size you want,
the length may be according to your wish, suppose the tube size is 1/4" inch then the width
of the piece is 1" inch, fig 1
Fold the piece in half lengthwise and sew the wrong side edges together, it means the right side of the piece is inside of the tube.the fig 2 and 3 are shown for you to clearly understand.
now you insert the edge part into the tube with the help of the stick. like fig 3.you push the wrong side piece in side.
The fig 4 shows the tube hole.
Start pushing the fabric down over the tube.
now it is creating more ruffles in the fabric. keep scrunching and sliding of the fabric until the fabric right side out.
Now you have the inside out through the tube . The below fig shows the stick is inside the tube and fabric right side is out side now remove the stick your work is done.
i have used this tube in my sewing project neckline