Step 4: Scoping your ride
90% or the time, you are going to get a smoker as a ride. If there is an open container in the car, or these people have been smoking weed, just say "Sorry, I was using this as a sign so my Sister/brother/Girlfriend/boyfriend could see me". Its as easy as that.
The best sign in my experiences to getting a safe ride is if they are a little suspicious of you. This signifies that they will watch you and you can watch them.
Make sure before you get in the car that you ask them where they're going, if it isn't in the direction you want to go, just say "Oh sorry, I'm not heading that way. Peace"