A million years ago I used to do coke/crank. I quit but then I used a couple times at parties. Everytime was really bad. I felt so bad about myself and how I behave. I made a rule that as soon as I found out there was something at the party I ran, not walked, to the nearest exit. I haven't used since. About 12 years now. I don't know if this works for everyone but if I gave my self time to consider it then I was in trouble.
Jenn