Read. Read everything you can. Read in the subgenre you write in. Read in genres you don't write in. Read newspapers. Read poetry. Read non-fiction books on writing. Read non-fiction books for research. The more you put into your suitcase, the more things you'll have to draw from when it's time to write.
Write. Write every day. Plan to write. Write at the kitchen table. Write while you're sitting at your child's sports/music lessons. Write on your lunch break at work. Learn to edit and be willing to cut out words you've written. Understand the craft of telling good stories. But you must write everyday.
Observe. Go on walks and notice the nature around you. Go on trips and wonder at the different people, places and sights. Sit in a coffee shop or cafe and watch the people around you. Then play the "what if?" game.