What are some techniques to practice Anatta with the five aggregates?

According to the [Anatta-Lakkhana Sutta](https://www.accesstoinsight.org/tipitaka/sn/sn22/sn22.059.nymo.html) , the Buddha asks us to treat the five aggregates (form, feeling, perception, mental formations and consciousness) as "this is not mine, this is not I, this is not myself". Since "this is not mine", "this is not I" and "this is not myself", the Buddha asks us to find 'estrangement' in the five aggregates. Are there any further techniques that we can use to help us achieve this estrangement? For example, in the Theravada tradition, Buddhist monks have said that if your ear hurts, think of it as 'there's an ear, and it hurts', rather than thinking "my ear hurts". So far, I have been using this method when it comes to observing my physical body. When it comes to feelings (e.g. anger, fear), it helps me to close my eyes and observe the feelings as an outsider. As I am observing them, I can feel them going away and myself becoming calm again. Is the above way of practicing estrangement correct? I would like to make sure that I stick to Buddha's original teachings/ theravada tradition. Thank you.