My guru was given one specific instruction by his guru (I consider them both my guru for reasons I may share another time), which was to take time at the end of each day to contemplate the day and what happened.
The meditation is to reflect on the day and notice what could have been better, what you could have done better, how you could have treated people better as well as what went right and how you might make it even better, or continue doing to be a better person. This incredibly simple practice is very powerful.
The only real way to tell if you are growing spiritually is if you treat people better. If you treat people better today than you did yesterday then you have grown. Making this your primary practice guarantees personal and spiritual growth!
The best time to do this practice is right before bed, or even when you go to bed. Take a few minutes and make an honest assessment of yourself and how you think you did.
How you gauge yourself has to be by your own estimation. It doesn’t matter what other people think of you, or their beliefs about what is right and wrong. And, it doesn’t matter what scripture says either. It has to be your true and honest assessment of yourself by your standards.
As you grow your ethics will develop and grow as you grow. For example, if you do something you think is perfectly okay, but someone is affected by it and they either tell you how they felt wronged, or you notice that it had a negative effect on someone, then you will realize that action really isn’t okay.
In yoga the highest practice is noninjury. The definition is to not do anything that will disturb the mind stuff of another. If you think about it you can see that this is almost impossible. Your mere presence could negatively affect someone!
The only way to achieve perfect noninjury under that definition would be to become a saint! As you grow and learn to treat others better and better, you will become more saint like.
Weather you achieve the ability to not affect people or not is beside the point with the meditation of reflecting on your day. The goal is to move toward that perfection. Any movement in that direction is spiritual growth. And, you can better achieve that by reflecting on your day looking for how, in your estimation, you can improve your treatment of others.