By working on a healthy self esteem. If you love yourself, you will not want to risk yourself or the peaceful mind of someone who you love.
What can be done to reduce risky behavior?
Put them in a padded room ... Strap them to a surface ... Handcuff them ... Get them treatment ... Get them education ... Etc, etc, etc
It all depends on WHAT "risky behavior" you are talking about.
See a doctor.