We can ambush sensations that affect our body. While meditating, we become alert to our senses. We wait for sounds, smells and mostly tingling or scratching sensations in our body. Instinctively, we may have an urge to react physically to what we sense.
When ambushing sensations, we make an effort to observe the sensations and refrain from a physical reaction. After observing the sensation for some time, it dissipates like passing clouds.
By focusing on sensations, we are shifting our awareness to what is happening in our body NOW.
We can then scan the body and check if there are other sensations, also minor ones.