Imagine the whole stream of thoughts is being projected onto a screen and you are merely an observer, watching them pass by. They are not yours, and you are not theirs. Feel your own existence, happy and complete, separate and independent from what is happening on the screen.
Like sushi on a sushi train, thoughts are passing by and it is up to you to select the ones you like. Select only the positive; absolutely reject the negative. You will be the winner.
With practise, it becomes easy to discriminate between positive and negative thoughts. Positive thoughts open our hearts; negative thoughts close our minds. Positive thoughts uplift and expand us, make us greater; negative thoughts bring us down and reduce us, make us smaller. Positive thoughts put wings on our shoulders; negative thoughts put lead weights on our feet. Positive thoughts nourish our beautiful smile; negative thoughts fuel our furrowed brow and dark frown. Positive thoughts free us; negative thoughts imprison and control us. Positive thoughts give to us and inspire us to give freely; negative thoughts take from us and incite us to take obsessively. Positive thoughts ennoble us; negative thoughts demean us. Positive thoughts serve us; negative thoughts enslave us.
Frequently throughout the day, pause whatever you are doing, and consciously observe the flow of thoughts: at this moment, are you entertaining positive or negative thoughts? Whenever you find they are negative, even slightly so, don’t hesitate: kick them aside ruthlessly before they take hold of you. When they are positive, embrace and expand them gratefully.
Vividly recall your morning meditation. Breathe in all its peace, light, beauty and happiness. In this way your meditation will remain alive the whole day through and protect you from destructive thoughts, your worst enemy.