Yoga is not something magical but merely a empirical discipline with an accompanying metaphysics developed over a long period of time within a cultural context. Tease out the essentials from the cultural context and you have a practical discipline relevant for everybody today.

For example, Patanjala Ashtanga Yoga gives an all-encompassing framework to learn to focus/concentrate and if needed, experience a distinct supra-normal mental state (i.e. Samadhi). But the last is not necessary and you could use the framework to do and feel better in the everyday activities of life.

Here is how to do it;

1) Yama - We are embedded in an environment which influences us. Thus we have to practice restraints w.r.t. the environment to settle on a equilibrium state where we can have some control over how we react to external factors.

2) Niyama - We are active living beings with certain essential everyday needs. These need to be automated away using personal discipline so that we don't have to think and waste precious mental energy on them.

3) Asana - Because "we" are housed in a material Body we need to take care of and maintain the body so that it is healthy, strong and free of diseases leaving us free to work on our mental aspects.

4) Pranayama - The Body and the Mind are linked through the Breath. Hence to control the Mind one needs to learn to control the Breath first.

The above are the four "external" aspects, the four "internal" aspects follow;

5) Pratyahara - In order to focus and concentrate on one thing we first need to "withdraw" our Mind from other things and this is the practice of such withdrawal.

6) Dharana - Now we focus on one thing; it will be momentary at first but with repeated practice becomes easier.

7) Dhyana - Now we hold our attention for long periods of time on one thing. This is commonly known as Concentration/Contemplation. For all normal everyday activities we can stop at this stage.

8) Samadhi - This is the state where the distinction between subject and object does not exist and the individual has "dissolved himself" (called "Laya" in Sanskrit). A good common example is when people laugh and cry (literally) with the protagonist when watching a emotional movie. The key here is to be completely permeated by the experience itself with no other thought/emotion/feeling (Classic example - Orgasm). In modern psychology this can be approximated by the "Flow State" - https://en.wikipedia.org/wiki/Flow_(psychology)

As you can see, the framework given by Ashtanga Yoga is eminently practical.