Mirrors on sliding doors.
Depends on how far you want to go with it. For starters you can replace the sliding doors with French-style doors. As for the inside...there are lots of items for organizing a closet and they are very customizable. Here are some ideas on Amazon.
The sliding glass doors probably visually enlarge the room. Without seeing the whole closet, I would suggest building a vertical "wall" or divider in the middle of the closet and then having 2 closet rods on one side for tops and for bottoms underneath. Keep a single rod for longer things. Depends on how many of each kind of item you have where the division should be. We can't see if there are shelves above the rod, but they (or it) can also be utilized to hold more.
Totally agree with Emily.
I used a Rubbermaid Configuration kit when I updated mine. It is in my projects if you would like to take a look. Just click on my name or picture on this answer.😁
Hi Rhonda, there are lots of organizing products out there at very great prices, here is a video to hopefully get you started
Also painting or pretty wall paper inside , rubbermaid and closet maid has great systems for organizing. What I did to get shoes off floor I place a curtain rod toward bottom of closet and shoes lined up nicely