Transparent Corp's Research Area is arguably the most comprehensive resource for collated brainwave entrainment research.   Update: the main research area on Transparent Corp's website is currently being updated, so it is offline.  However, you can still access their peer-reviewed research paper as a PDF here: “A Comprehensive Review of the Psychological Effects of Brainwave Entrainment“.
^ Trost W. and Vuilleumier P., Rhythmic entrainment as a mechanism for emotion induction by music: a neurophysiological perspective. In The Emotional Power of Music: Multidisciplinary Perspectives on Musical Arousal, Expression, and Social Control, Cochrane T., Fantini B., and Scherer K. R., (Eds.), Oxford, UK: Oxford University Press; 2013, pp213–225.
In other words, you give the well a little taste of what it is you want from it, and then the well responds by delivering more of the same back to you. In the case of the water well, you pour a small amount of water down into the pump. This is known as “priming” the pump. Until you do this the pump does not produce the water you’re looking for. Once you prime the pump it sets up the conditions in which that pump can do its job and the water begins to flow.
Beta brainwaves are typically those we experience when we are wide awake and full of energy. You can think of this frequency as the equivalent of taking stimulants like caffeine, Adderall, or various nootropics. The Beta frequency is good for generating a concentrated, focused, and analytical mind. In fact, the brainwave you probably possess while reading this is of the Beta frequency.

The reason this rule of thumb is so useful is because there is a huge market for simple answers. A genuine elegant solution (one that accomplishes more with less) is highly valuable in the marketplace. We are used to technology delivering new easy solutions to previously difficult tasks. While most improvements are incremental, there are occasional breakthroughs that transform our lives.

It takes slightly more time to practice guided imagery, but this is a great way to leave your stress behind for a while and relax your body. Some find it easier to practice than meditation, as it allows more engagement of the conscious mind. You can focus on imagining relaxing environments you would love to visit, or on memories of your "happy place" for when you're stressed. You can play natural sounds in the background as you practice, to promote a more immersive experience.

Experts haven't figured out why having your body pressed and prodded works wonders, but they know that it does. Studies suggest massage can speed up weight gain in premature babies, improve lung function in asthmatics and boost immunity in men with HIV. If you can't indulge in regular full-body massages, treat yourself to the occasional pedicure, manicure or facial—all nurturing, hands-on treats that offer some of the mind-body benefits of massage. 
Well, except for one reason: The power of suggestion. If I give you a music track and tell you that it will cure your headache, you're more likely to report that it cured your headache than you are to say "Well it didn't effect my headache, but it made my short-term memory better." An interesting experiment would be to buy a binaural track claimed to induce drunkenness, for example; play it for five friends without telling them the claim, and then ask how it made each of them feel. Give them multiple choices to select from. Chances are they're going to respond all over the map. If you have a friend who is a believer in binaural beats, I suggest going ahead and setting up this little test.
We can’t always control sources of stress in our lives, but we change how we react to them. The good news is this: The human body is actually designed to experience and handle stress, which is exactly why our bodies react to it so strongly. With some practice, we have the power to learn to use certain elements of stress to our advantage (for example, the fact that stress keeps us more alert and attentive), while better controlling other negative reactions (like digestion problems or giving in to cravings for unhealthy foods).
You know how movie characters always look themselves in the restroom mirror when faced with a tough situation? Well, giving yourself a quick pep talk in the looking glass can actually help relieve stress. “‘Mirror work‘ is done by looking in a mirror and vocally speaking positive affirmations to yourself with affectionate conviction, to release worry or to improve your self-confidence,” Whitaker says. To relieve stress in the moment, she suggests using a restroom mirror, your car’s rear-view mirror, or even a compact. “Calm your mind by saying encouraging affirmations aloud to yourself, such as, ‘I am excellent at what I do,’ ‘I’ve got this! I am amazing,’ ‘I am an asset to this company,’ or ‘I am awesome!’” she says.

♥ I admit that I do not know much about brainwaves and can be swayed by suggestion (ah, the fickle subconscious), but since using this machine and sort of hiding the noise with other sounds or my own music so it is not so obvious to me, it has helped me get through my email correspondences and other online tasks with the focus that I need. Thank you so much for making this!
A study published in Electroencephalography and Clinical Neurophysiology by Paul Williams and Michael West in 1975 examined the brainwave states of people experienced in meditation while using photic stimulation, and another study by Leonard, Telch, and Harrington in 1999 examined the successful use of brainwave entrainment techniques for attaining meditative states in subjects.
And so we (not too surprisingly) begin to experience “symptoms” or “signs” of something that we do not ordinarily experience. Immediately, we associate these with the entrainment or the meditation. We wonder if this is something real or imagined so we often start asking others if they have experienced the same or similar things. We seek validation that our practices are producing tangible effects on us.
You may not always be in the mood for meditation when your thoughts are racing, though it is a powerhouse of a stress reliever; you may sometimes face relationship stress that isn't as well-managed by breathing exercises (another highly effective stress reliever) as it might be by learning communication techniques. Guided imagery is fantastic for before bedtime while games are an optimal stress reliever to share with friends.

Entrainment is a principle of physics which appears in biology, chemistry, neurology, medicine, astronomy etc. It is defined as the synchronization of two or more rhythmic cycles. In the seventeenth century, Dutch scientist Christian Huygens found out that by placing two unsynchronized clocks side by side on a wall, they would slowly synchronize to each other in a very accurate way. The clocks were the first example of spontaneous synchronization, a phenomenon found throughout nature from cells to the Solar System.
4. Be hesitant committing to any BWE system making wild claims. Profit fueled marketers with little to no experience in the BWE field have created a slew of low-quality entrainment systems on the market. These products typically make outrageous promises such as permanently enhancing the brain within minutes of use. Although BWE is a powerful method to improve the mind, it’s not a magic bullet.
There are countless techniques for managing stress. Yoga, mindfulness meditation, and exercise are just a few examples of stress-relieving activities that work wonders. But in the heat of the moment, €”during a high-pressured job interview, for example, or a disagreement with your spouse, you can’€™t just excuse yourself to meditate or take a long walk. In these situations, you need something more immediate and accessible.
^ Trost W. and Vuilleumier P., Rhythmic entrainment as a mechanism for emotion induction by music: a neurophysiological perspective. In The Emotional Power of Music: Multidisciplinary Perspectives on Musical Arousal, Expression, and Social Control, Cochrane T., Fantini B., and Scherer K. R., (Eds.), Oxford, UK: Oxford University Press; 2013, pp213–225.