Every first draft is a skeleton. It does not need to be perfect yet. Add some depth with time and patience, and you will get the complete body.
Write something you, yourself, would love to read over and over again because that is exactly what you will be doing until you feel the drafts have reached its final, publishable position.
Aim for perfection. It is that personal strive for perfection that helps you produce the best quality of written work.
When you think you´ve lost your imagination, think of the most ridiculous thing that could happen like flowers verbally exchanging secrets, a garden growing out of your bedroom floor or a painting coming to life.
If stuck on how to begin, start at the middle. Also, try to give yourself sentence starters or begin with a famous motivational quote. You can even start with characters engrossed in dialogue.