Roll the clothes and then place them vertically. This will help you see what clothes are what and stay organized.
- Wrapping rubber bands around the clothes helps them stay folded.
- You can use CD cases(as dividers) in a rectangular box to make them stay up.
And another way to address the extra room problem:
Besides this take some books or other "space Fillers" and put them where the clothes used to be as you remove clothing.
Taking a box and filling it with clothing items or other items and when you remove enough clothes put those in its place. This keeps clothes standing up straight vertically.
- Also, laying clothes down flat after the drawer gets empty to a certain amount, may help.
Additional Info
WikiHow: Basically how to fold clothes, but this only works if you have clear containers, or other storage options as shown below.
Folding T-shirts vertically.: Basically you fold the shirt in half so that it is a long rectangle and then you refold it into square blocks.
53 Seriously Life-Changing Clothing Organization Tips
Adjustable drawer organizers keep your clothes in line.

A alternative to this is taking a rectangular container and putting dividers in it, these can be CD cases or other items you find helpful.
For super-neat folded clothes or towels, install wooden shelf
dividers.

These can be made yourself or you can use a book or book end(these work better).
Take containers and put them on edge. Somewhat like this:

You can fit all these methods in a drawer if you get the right size containers and dividers. And using multiple methods really help, as well.