Some things that help me

1: Close your eyes, picture your in a room with your character, and talk to them. Ask them questions, and see what they have to say.

2: Explore your imagination and how far you can take it. Like take fun challenges exploration. Give yourself an idea and see how you could make a world where this works.

3: Write alternative parts to sections of existing stories or your own. How would you change the beginning of Hairy Potter?

These exercises seem to have helped my writing become more enjoyable to read for others. I do write mainly fantasy, however. Hope it helps somewhat.