Obviously a beginners job, a couple of quick comments. Play around with the different masking tools, particularly the pen tool, and have a go with dodge/burn to get some depth in the cloth - add creases, shadows and highlights. Have a play and look at some online tutorials - but keep practising and having fun!

Ray can you suggest me a online tutorial page for this only..? Pls...

ahahahahaah !!! they look sooo sexy ;P

Try to upload a higher res whenever possible. You can also play around with liquefy, it might help but dodge and burn is a good choice too.

High res. done jaws..... But I am not happy with the result

AUTHOR... simply change the Opacity on the towels placed over the originals towels.. this will cause the textures and shadows from the back towels to shine through.. or you can use burn on the surface layer of towels and follow the shadows on the original picture to figure out the placement.. you still have time.. just make sure to use a super soft brush and gentle motions to darken the towel material.. (displacement map would be a good route as well) good luck

When you upload a high rs, check the box that says, "Upload High Res"... Next time, ok???