If you want to be happy, it helps to be healthy--in mind, body, and spirit. But just like sporting an ideal weight takes intention, it takes practice to cultivate the mental habits that will spur you to be the best version of yourself. Here are several daily rituals you can start practicing today that will yield a wealth of benefits.

1. Stop criticizing others, even in your mind.

This is easier said than done, considering what psychologists call "negativity bias." Here's what Lea Waters, PhD, author of The Strength Switch: How the New Science of Strength-Based Parenting Can Help Your Child and Your Teen to Flourish, writes on the subject:

Even people with the sunniest personalities have what scientists call a "positive-negative asymmetry" and will pay more attention to negative rather than positive information.

Because this bias happens at the fundamental information processing level, it's present in everything we do: how we react to events (good or bad), how we develop trust in relationships (or don't), and how we learn. When you first meet someone, you'll automatically place more weight on what you find wrong about him or her. This asymmetry endures: That person will have to do more good acts to undo a negative first impression than bad acts to undo a positive one. Bottom line: Bad impressions are easy to gain, and good reputations are easy to lose.

Work against this human tendency to gravitate toward negativity. Instead, stop making assumptions and find the positive aspects, traits, or qualities of the people in your circles.

2. Quit drinking alcohol, just for a month.

Folks who like to kick back at the end of the day with a cocktail tend to do it in stationary mode--sitting in front of the TV, for example. Instead of imbibing, switch out your habit for something else, such as walking with your mate or dog, or working on a big domestic project you've been putting off. The reality is that people who drink frequently at home spend a lot of time doing so. Try it for just 30 days--chances are you will be shocked at how much you can get done.

3. Exercise, even a little bit.

I feel like a rock star when I get back from a three-mile run. But honestly, half the time I don't feel like putting in all that effort. It's OK. Instead, do 100 pushups (even on your knees) or a bunch of squats. As long as you do some kind of exercise every day--whether it's weightlifting or aerobic--your body will look and feel better.

4. Read something inspirational.

Spiritually minded individuals stay close to the Creator by spending a few minutes a day contemplating scripture. If holy writings aren't your thing, countless high achievers credit the great books they've read for inspiring them to strive for greatness. You only need to devote five minutes to this practice.

5. Do a good deed.

Give someone your spot in line, buy a co-worker his favorite morning drink, or call your mother and mindfully listen to her tell you about her week. Even little things can make a big difference in someone's day. Plus, researchers have found that performing acts of kindness make people feel happier.

6. Replace one meal a day.

I prefer pizza over salads, but feel better when I force myself to drink a healthy smoothie instead of eating something rich and savory. Try any of Angela Liddon's recipes, starting with this one, called "Happy Digestion Smoothie."

7. Spend time in nature.

Researchers have found that spending time in nature improves cognitive functioning, attention, and memory. Urban environments are filled with stimulation that requires attention. "Nature, which is filled with intriguing stimuli, modestly grabs attention in a bottom-up fashion, allowing top-down directed-attention abilities a chance to replenish," the study's authors write.

8. Get up before the sun.

Hundreds of CEOs, founders, and other successful executives have weighed in on the daily habits that help them succeed in life, and rising early to meditate or exercise is commonly credited for helping them get ahead. "[My company] was built on the work I did for five years every day between the hours of 4:30 and 7:00 a.m. It sounds hard, but it's not," says Abraham Piper, founder and chief creative officer of online publisher Brainjolt. "Just drink a couple of glasses of water before bed so you'll want to get up to go to the bathroom between 4 and 5 a.m. And then just stay up. Everyone else will still be sleeping. And when people are sleeping, they can't expect anything from you. It's your time."