I struggle to get jeans that fit at the moment (size 18/20 and still carrying a spare tyre from pregnancy).
I have a couple of pairs of jeans (brown and burgundy) from john rocha (I think) that fit really well at first, then as the day goes on they get more and more baggy (I can pull them off without undoing them) and they look awful, especially baggy around my bum.
The only pair I have that don't do this is a pair of next wide leg jeans, they seem to have the right amount of elastic to meet sub their shape. But they don't sell them any more 
I tend to go for wide/boot cut/straight leg at a push as skinnies do me no favours at all - can anyone recommend some that might suit/keep shape?