I do find that watercolor landscapes can be challenging due to the amount of time and paint needed!

I'm sure this will sound trite but practicing every day for at least 15 minutes has helped me tremendously. Especially before bed, as I see better improvement that way for some reason. Aside from that, I'll list some tips that helped me on my self-taught watercolor journey:

1) utilize tools such as cotton balls or cotton swabs to pick up excess water and blend colors while they are still wet by dabbing them.

2) patience is key. Allowing each layer of paint to fully dry before moving on is important. Sometimes even pausing at a difficult spot of your work and waiting until the next day to carry on can be helpful in gaining some perspective.

3) it's easy to lose the highlights of the landscape (or anything you're painting really) with watercolor, because as you go on and add more paint, things can get murky. I keep thin, white acrylic paint handy to finish off a painting and make sure the highlight is not lost. It makes a huge difference.

Good luck and don't give up! You got this! :)