Figure out what you want to see and do on your coastal getaway. For example, are you interested in visiting a large city like San Francisco, or a small community like Carmel? Do you want to walk along the boardwalk in Santa Cruz, or hike along the cliffs in Fort Bragg? Narrowing down what you want to see and do on your trip will help you plan a fulfilling getaway.
Research your trip. This may involve talking with a travel agent if you do not know where to start. Also, Lonely Planet Online has a traveler's forum and planning center to help you discover things to do on your trip. If you live in California or out of state, decide how you are going to get to your destination.
Reserve a place to stay on your getaway. Consider staying in a bed and breakfast or camping instead of a traditional hotel. Decide if you are going to rent a car. Purchase travel insurance if necessary.