Instead of creating a huge list of goals at the beginning of the year, set a small goal weekly. If you want to join a gym at the beginning of the year, by all means do it, but don't punish yourself by telling yourself you're going to work out religiously and by February, going once a week and feeling bad about it. Set attainable goals that you know you can achieve and build from there.
You can always sign up for a new gym and start going twice a week. Maybe some weeks, you'll go more frequently, and maybe some weeks you'll only go once. Set the goal for going once a week. Give yourself some wiggle room. If you start your goal at "I'm going to go 5 times a week", you're going to burn out by February or March and end up not going at all. You'll find yourself on the sofa eating Cheetos, feeling like shit, because you failed at your New Year's resolution to become a gym rat.
Instead of setting a goal stipulating that you will go on a diet, make a list of your guilty pleasure foods and which days you indulge the most. Do you eat big meals, or just graze all day with snacks? Which time of day do you binge? By analyzing your routine, you can pinpoint when you are eating the most and what you are eating the most and worst of. For example, if I eat ice cream Monday through Friday night, I could set a small goal for myself to not eat ice cream one night during those five days every week. If by the end of that month, I feel that I should increase it to not eating two nights Monday through Friday, then I would set another goal. Small goals over time create the most change.
Instead of focusing on resolutions, take a look at the unhealthy, ineffective patterns in your life. Then ask yourself "How can I make this better? What do I need to change? How can I switch up my routine? And how can I do so without failing?" You have to always keep in mind that you are a work in progress.
Some weeks you are going to fail, and that's okay. Just focus on the next week. There is no need to be self-critical. You may fail one week, but you are far from a failure. Keep it movin'. A week is just a week. Move on to the next week and do better. At the three month mark, you're going to look at your progress. Ask yourself "How do I feel compared to when I started? How is my progress coming? What do I need to improve? Do I need to make changes to the goal itself?"
You may decide that since your progress is going so well, you want to increase the goal. For example, I might be going to yoga twice a week, and I'm feeling so positive about my weekly routine that I wish to increase my goal to three times a week. Or I may have set a goal to go to yoga twice a week, but I'm only making it in once a week. Decrease the goal, but look at what's holding you back from not hitting it. The key is to recognize your patterns in your routines and make changes.
Be easy on yourself. Love yourself. Focus on your happiness first. Believe in change and how it can work for you and know that it's more simple than it seems. Don't take on more than you can chew. A small goal can easily gain incredible results in the end.