I have the opposite problem - if I'm thinking too hard near bedtime about financial math or boolean algebra for example, I won't be able to sleep. My brain is too active going through all the calculations in my head.

If I want to fall asleep within 5 minutes, what works for me is varied physical and mental exercise throughout the day, and an easygoing book or movie near bedtime.

If there's something stressful going on the next day, a tech-nerd podcast like ATP helps me forget about it and get to sleep. But I try not to let late night podcasts become a habit - sometimes they get too interesting and I stay up for over an hour to keep listening.