well after i twist my hair and put into juda, it instantly falls apart.ok, if you can twist your hair into a juda, then you don't need a rubber band, can't do much about the shape, but Kesh is not what shape your juda is, as long as its a juda. If you have achieved Juda-ism (not Judaism), (I know its just semantics), then your there.
I am afraid I cannot assist you with the look as such, but its still Juda, be proud of it!
Or use several, the ones shown in the picture. My son uses the first one to put all his hair together before even making a joora. Use one at the end after twisting your hair and use 4 or 5 to keep it all together. Trimaan's hair is below his knees and quite thick.If your hair is long (may be very thick or heavy) and your joora still falls apart after you wind it up, use some inexpensive hair gel so that the strands will hold together.