Regardless of what you resolved to do in the new year, you won't get very far without some good habits in place. This weekend, take the time to understand how to make better behaviors stick and rid yourself of the old ones.
Understand the Psychology of Habits
It's hard to form a good habit if you don't know how they work. Most of them form thanks to a cue-routine-reward system. This means you have a cue that triggers the behavior, a routine you go through as a result, and a rewarding feeling you receive at the end. You can use this to understand bad habits and form good ones. It exists at the basis of pretty much everything you do regularly.
You also need to pay attention to willpower or you will burn yourself out—unless you're really good at realizing this is all in your head. Don't try to break all your bad habits and create lots of good ones at once. That's a recipe for failure. Take things slow and only tackle one or two at a time. Try a 20 second rule to avoid overdoing it. Slow progress is better than nothing at all. Also, it turns out that physical exercise can help you develop better behaviors. If you've resolved to add a regular fitness routine to your schedule, that's a good place to start.
Get Rid of Bad Habits
Bad habits can be very hard to break in the first place because you can perform them without realizing. Biting nails, for instance, just sort of happens and by the time you've had your first nibble the damage has been done. To avoid this problem, you need to remind yourself of why you don't want to engage in this default behavior regularly. Tell yourself the harm each time you catch yourself engaging. I did this with a webcam, recording myself explaining what I wanted to accomplish and why and then forcing myself to watch it every night. Nail biting was the only bad habit I struggled to break with no other methods working. This one did, because I created a habit of remembering how much it mattered to me.
The important thing is to keep your plan simple. For some, that doesn't mean much more than an if-then cycle. The more work you make yourself do to break a bad habit, the more you're going to wish you weren't doing it. Breaking the habit is difficult enough, so don't add unnecessary complication. Whatever plan you choose, make it a straightforward one.
Make Better Habits
Creating good habits is fortunately a lot easier than getting rid of bad ones—you just need to repeat a behavior until it gets stuck in your routine. The easiest way I've found to do this is with Jerry Seinfeld's productivity secret: don't break the chain. You basically plan to do something once a day and every time you do it you get a checkmark, gold star, or whatever you want on a calendar. This creates a chain of days, and once it gets long enough you won't want to break it by missing one. If you're a little obsessive like me, this is a very effective strategy. You can even use an app (for Android or iOS) to do it if you don't like paper calendars. Just remember to be patient. For a long time we believed it only took 21 days to form a habit, but that's actually wrong. Give yourself a few months before you assume you've programmed yourself for a new routine.