I've done this for years as well! :D

At first, I could only remember feelings. My first dozen or so dream journal entries are things like "a warm fog", "a happy environment with yellow light", "I had to protect something", etc.

Then I started remembering details like a rock, or a staircase, or a tree, etc.

Finally, once I kept writing for a month or two, I started remembering more and more events. The more I did it, the more detailed they were. I kept writing all the details. I spent one day around an hour and a half just writing down all the plots, subplots, themes and ambiences in a dream, writing down the feeling everything gave me and the physical characteristics I could remember.

After doing that a few times, I decided to stay moderate, but ever since then, my ability to remember dreams has increased massively. I owe it all to disciplined and detailed dream journaling.