Yes, you want to see results from your healthy habits, but that doesn't mean you have to go from zero to 60 overnight. Making small changes is more likely to stick than overhauling your entire life (and diet) overnight. So, start with something manageable - like adding a 10-minute walk to your daily routine or giving up soda for a week.
Once you've decided on a healthy habit you want to form, do what you can to make it automatic. This means keeping things as simple as possible and having as few decisions to make along the way. For example, if you're trying to eat breakfast every day, choose a breakfast that you can easily make without thinking about it (a bowl of cereal or piece of fruit) and put everything you need for it in one place so you don't have to search for it or make any decisions first thing in the morning.
If there's one thing that's sure to derail your healthy habits, it's feeling like you're depriving yourself. So instead of cutting out all of your favorite foods, focus on adding more healthy foods into your diet. Not only will this help you feel like you're making progress instead of taking steps backwards, but it's also more sustainable in the long run. And speaking of the long run.
It can be easy to get discouraged when forming new habits, especially if results aren't immediately apparent. So keep your goals in mind and remind yourself why you're doing this in the first place (even if it's just smaller jeans). Write down your goals or keep pictures of them where you'll see them every day as a reminder of what you're working towards.
Finally, give yourself credit for making progress! Forming new habits is hard work and deserves to be celebrated - even if it's just with a mental "pat on the back." Once you've reached a milestone or made it through a tough week, treat yourself in a way that doesn't undo all of your progress (like buying yourself a new book instead of a box of cookies).