The main difference is female jeans tend to be lighter material, softer fabric and some are made of stretchy fabric. They tend to cup the ass nicer too and dependant on the cut are tighter also. The pockets are not really functional in womens jeans they are so small.
On traditional female jeans the button is on the opposite side to male jeans, thats not that common these days and stating the obvious they are not designed for a cock so they can bulge and definately so when caged, which i am permanently. Tighter knickers help reduce this.
Avoid hipsters they are designed to fit higher on a female hip and drop down on men and look baggy, i find the best place for jeans at the moment is Sainsburys, straight leg ones in blue or black at £16. Decent tight female jeans are not unfortunately in fashion at the moment so thay are becoming harder to find.
Skinny jeans are very small in the bottom of the leg, i certainly cant get my feet through the bottom.
Uk sizes: male 34", equals size 12 to 14 in female sizes, this varies by shop however. I have a pair of Marks and Spencers 10s that are heavier fabric but fit me snuggly, my cuckoldress likes these. I am a size 34 and wear as my 2normal" everyday jeans both 12s and 14s straight legged, the 12s are tighter obviously.