Good afternoon, friends!
Mindfulness is a way of paying attention, and at it's essence is the idea that one withholds judgement. It's a way of practicing being present with an attitude of acceptance, rather than seeking what is wrong or right with a thing (person, idea, experience, etc.). Mindfulness practice is potent, powerful, and highly useful for many things and in multiple directions.
There are other practices one can do to support a healthy and resilient self, and some of these practices have to do with using intention and breath to transform negative feelings into positive feelings.
Imagine, if you will, something that causes you anxiety. For me, crowded elevators are always a source of anxiety. I could engage in mindfulness while in a crowded elevator, taking a detached perspective and observing my responses and reactions without making them right or wrong. I could also practice transforming anxiety into another emotional state all-together, and then draw on that while in the elevator.
The techniques I'm sharing here are best learned from a teacher. Please consider the following as me sharing information - you can try some of it out if you'd like, and if you feel resonant - find a teacher. I teach these techniques, and if we aren't proximal, we can work via Google Hangout, and I'd be happy to find someone in your area as well.
In Esoteric Taoism, which is a vast and complex system that includes paths for solo and paired practice, the first thing I learned was The Healing Smile. To do the Healing Smile, all you (and I) need to do is smile to the body/mind. Just as it is. So if there's a broken leg, you smile to the broken leg with love and compassion. The core practice takes about 10 minutes, and you will focus on the three main energy centers in Taoism: Tan Tien (dawn tee'-in). The lowest Tan Tien is in the enteric brain and it connects us to earth energy. In several martial arts, this is called The Hara. It is a place of great personal power. The middle Tan Tien is where the thymus gland is/was. The thymus gland is largest before puberty, and as we age, it gets smaller and smaller. This is the heart-center, and to me, it's about connecting with others from a place of compassion. The upper Tan Tien is in the middle of the brain, and home to the pineal and pituitary glands. The pineal gland produces melatonin, while the pituitary gland, which controls the function of all other endocrine glands. In Esoteric Taoism, the upper Tan Tien is also called the Crystal Palace.
Here is an audio file that guides you through the Healing Smile
After directing one's Smile to the three Tan Tiens, the emotional alchemy begins. Using the Healing Smile, specific breaths, and intent, you practice cultivating good feelings and transforming challenging emotions into more comfortable emotions. There are 6 breaths in total, 5 of which correspond to major organs in the body (lungs, kidneys, heart, etc.), and the final breath which holds within the intent to cultivate equanimity (even-temperment).
This video provides an overview to the practice, so you can get an idea of what is involved and take any notes you feel would be useful.