My doctor recommended that I take up some type of meditation, mentioning “mindfulness” as one option. I understand that this particular meditation is connected to idolatry.
Are there Jewish meditation techniques I could use?
Mindfulness is a Jewish idea and it is called kavanah.
Take one page of the siddur (prayerbook), and learn the meaning of each word on that page. Learn it as deep as you can. Or maybe, instead of a page, you should start with one line of the prayers—such as the Modeh Ani or the Shema Yisrael.
Practice saying each word with clear mental focus. Ignore any other thought that enters your mind. This is called kavanah.
Slowly, you can build up through the siddur until much of your morning prayer time can be spent in this state.
The same applies to all the blessings on food you say during the day. And eventually, every act of living can, and must, be done with kavanah, for the sake of heaven. As Solomon the wise taught, “In all your ways, know Him.”
Conscious breathing or some other technique could help as a preparation to this exercise.
For some more detailed guidance, here’s a place to begin your journey: The Jewish Meditation Series: Guidance on Mindful Prayer.