Is it possible that your are not drawing your line at a deep enough angle?
You can practice your folds using paper. This is what I do to see how the final result of a specific fold may look w/out wasting fabric/dye.
I have a stack of cheap/thin "printer" paper that I bought at the dollar store that I use. I fold it just as I would a piece of fabric. I draw a line just as I would on fabric when doing a mandala(or other fold). To get this line to repeat through the layers of paper I crease the paper at this line so that all the layers will have a crease along the same line. Unfold the paper and you will see your pattern.
Hope this helps
Kathy