Set reasonable goals; not something vague and unrealistic like "I want to be super-model skinny." I always had visions of very thin actresses in my mind when I was at the gym and it seemed so unattainable that I would quit any health regimen before it even got off the ground. But when I changed my mindset to focusing on making the healthiest choices possible for myself, it was a lot more realistic, more attainable, and then the results were visible.