Figure out short hang and long hang and rearrange rods. Visit closet design showrooms to get ideas.
Add a second rod so that you immediately double storage. You may need to have a small area with full length unless you wear mostly dresses, then that is out.
Use flocked thin hangers, huggable hangers are my preference because they are most durable.
Use a round hook to hang multiple tank tops on one hanger.
Tier hangers if you don't double the rod. Soda tabs will work for an inexpensive option.
Utilize the area above a rod with shelving or bins.
If shoes are an issue, install shelves or racks for them.
Joann: I know this is crazy simple... but I got more storage simply by doing this --
...and always use those slender flocked hangers!
I changed my hangers to ones that were all the same. I use the thin plastic flocked ones. This made slot of difference. I also put up two rails. I measured my longest skirt and then fixed a pole to take this, then I measured my longest top above the skirt, where the hanger hook was I fixed another rod. Before you fix this make sure you could reach the hanger.