First, make sure you know the cannabis laws in your state. It's illegal to use cannabis in public -- that includes everything from sidewalks and roads to parks, sports stadiums, music venues, and retail businesses. You can use cannabis on private property only, so it's best to stay home or at a friend's place. Also, remember that landlords, businesses, hotels, and other establishments may have their own policies on cannabis use, so be sure to check first before using.
Don't consume while you're in the car, whether you're driving or just along for the ride. When it comes to driving, cannabis consumption is treated like alcohol and is governed by policies similar to open container laws, so it's best to keep your cannabis locked up and out of reach in the trunk of your car when traveling with it (and make sure you don't cross state lines with your product).