Bringing any type of drug into or out of a country is illegal in most places, so don’t bring them with you when traveling (or at least make sure it’s legal first).
Driving under influence of drugs is also illegal in most places, and for good reason. Do not drive under influence to avoid any problems.
Many places do not allow the use of drugs in public, even when they are legalized for recreational use. Make sure it is legal before lighting a joint in a public place.
The so called Evergreen State, Washington is one of the states that are very friendly to cannabis consumers. Marijuana was legalized for medicinal use since the 1998, and residents voted in the legalization for recreational use on November 2012. The residents of Washington have a very positive view of the plant, so they are very accepting of people who choose to use cannabis products even for recreational use. In fact, there is an iconic yearly event hosted in Seattle called Hempfest, where you can see and feel the relaxed nature of the residents, while the police hands out munchies and teaches about marijuana laws in the state.
Recreational users of various marijuana products will have an easy time finding a place to buy their favorite strains, since there are many shops that opened up for recreational use since the sale of cannabis products became legal.