What mindfulness is.
You don't need this for mindfulness.
Mindfulness is a defined as "a mental state achieved by focusing one's awareness on the present moment, while calmly acknowledging and accepting one's feelings, thoughts, and bodily sensations, used as a therapeutic technique."
This is an expansive topic and multiple articles could be written on this subject.
It is essentially NOT pushing your thoughts you have out of the way. You are focused in the present moment and accepting what you feel. For example, if you are pissed, don't suppress. Truly live and experience those emotions. If you ride the wave rather than suppressing your feelings, you'll more likely get resolution and peace.
Though the population was with older adults, a randomized clinical trial showed improvement in sleep quality in subjects who practiced regular mindfulness meditation.
Part of mindfulness is mediation and being in a relationship with your mind where you can acknowledge your worries and push them away.
Consider watching this low-quality video by Dr. Jan Kabat-Zinn as he explains what mindfulness means.
It doesn't need to be done before sleep. In fact, I continually practice tiny bouts of mindfulness throughout the day so my stress levels are as low as I can have them.
Are you ready to practice small bouts of mindfulness? 3 minutes a day can transform your day outlook, and sleep.