Here is my ruffler if you aren't familiar with the dinosaur looking contraption:
The #'s indicate how many ruffles are taken-0 is for straight stitching, 12 is a gather every 12 stitches, 6 is a gather every 6 stitches and the 1 is a gather for every stitch [this is the mode I use most-if I am going to ruffle, I want to really ruffle]
On the machine:
To keep the roll of tulle in control, place it on a dowel in a box-rolls off easily
On the floor to feed through the machine.
Going through ruffler-gather per every stitch
Yards of ruffles quickly and easily
The roll of tulle has 100 yards. Rolls of 25/10 yards are also available. Of course, these are all bought on sale or with coupon. I have lucked into after season sales for the 100 yard rolls for about $2-3 at Hobby Lobby and get all I can afford that day. They are usually priced at $9.99. Regular fabric gathers just as easily as tulle.
If you don't have a ruffler here is my video tutorial for gathering by zigzagging over yarn @
They are perfect projects for a beginner sewist.