Here’s some images that appealed to me. Your single door is an issue, though. I think you may want to start by changing to a folding door for best access.

Removing the door and wall fronts to create a built in armoire would be a good looking solution.

If you have space in your bedroom, a storage bench could house a lot of shoes to free up space in the closet. It would also provide a handy spot to sit while putting on your shoes.

The first thing to do is inventory your belongings and figure out how much tall hanging space you need, how much short, and whether you need any drawers or shelves. If you haven't already tried to get rid of things you don't really need anymore (the easy part, right?), do that. If you have another closet where you can put out of season or infrequently worn items, get them out of the picture. Once you know what you want to store I think the rest will fall into place. For ideas, look at how standard closet systems deal with your type of space. Closet Maid - Home Depot, Elfa - Container Store and Ikea. It's not a big closet so there aren't going to be a lot of different ways to do it.

Transitional Closet · More Info

No Closet Too Small! · More Info

This is my favorite photo of a built in look. In your case, it would be about half the width, but could go all the way to the ceiling.

My Houzz: Art and Colorful Finds in a Manhattan Apartment · More Info