If you are interviewing for a new job, first of all, never forget to express how hardworking, dedicated and reliable you are. Also, add a few of your best personality traits, like compassionate and understanding.
But most important, be up-front about what you want. Most employers really do want their employees to be satisfied with their jobs because then they will be at their most productive.
Perhaps there are certain perks or job requirements or workplace conditions that are very important to you. Don't just assume that you will or won't get them - speak up.
Otherwise, you could arrive at your new job on day one and discover it wasn't what you thought you'd agreed to at all!