Feel grateful for the things you love and make you happy. Feel what if the day goes amazing and you will continue finding the good things all day long.
So what, a negative thought, comes to your mind? Just flip it into a positive one. Only entertain the best-case scenarios in your mind.
Meditation is a great way to relax your mind and get clarity on what you want. Let the universe know your desire and trust in its arrival. Till then, be grateful for what you already have.
During sleep, our subconscious mind takes over completely. So make sure only good thoughts and positive visions of the future enter your mind.