Mindset is truly the first most important aspect of weightloss. This not only includes commitment, but knowledge. If you don't first research healthy ways to manage weight--willpower can either be useless or even destructive (IOW-you may give up easily as you gain all the weight back or develop an eating disorder).
It's important to know which diets are actually healthy and have long-term effectiveness, and it's also important to view weight management as a lifetime commitment. There are a lot of so-called "articles" in magazines (especially ones geared to women) that advocate very dangerous ways to lose weight (frequently followed up by glossies of
recipes for high-calorie desserts).