Look where you mind goes. If it jumps to a pain know you attention is on the pain. If it is a thought know that it is with the thought. If your attention is on a ___ just know that your attention is with ____.
With each object your mind jumps to there is a sensation attached. If it a pain it is unpleasant. If it is sweet memory it is pleasant. If it is a birds chirping it can be neutral. What ever that grabs your attention just know the sensation.
In all these cases for each sound you experience though through your physical senses there is a metal reaction also which is also either pleasant, unpleasant or neutral. You should maintain equanimity so you do not get the mental reaction. In addition try to see in impermanence of each experience. All experience has a start, middle and and end. Also if you diver the sensation into smaller areas and examine them, large sensation is made up of smaller sensations clusters which shorter lived than the affected area. You can continue this division seeing more subtler and subtler clusters until you come to a level it is indivisible and changes seem unimaginably rapid. In addition you will see because of stimuli at the sense faculty only the some sensation started and when that simply subsides the stimuli the sensation disappears. You are not in control of the stimuli nor the pleasant experiences which you might want to prolong or unpleasant which you might want to shorten or get rid of.
Also developing the Jhana factors of:
- bringing the mind to the object
- sustaining the mind on the object
may help you develop more focus.
Also your meditation is not entirely in your control, i.e. it is non self, hence having expectation will be counter productive. Also getting attached to these expectation can be more counterproductive and it will cause unsatisfactoriness with the meditation. So practice the meditation techniques to the best of your ability without expectation or attachment to the expectation.