Right Thought

Brothers, practice Right Thought.
Right Thought consists of thought in which there is neither confusion nor distraction, neither anger or hate, neither desire nor lust. ( Vinayapitaka, Vibhanga Sutta )
Brothers, Right Thought consists of thought in which there is universal love. ( Suttapitaka, Majjhima-Nikaya, Piyajatika Sutta )

But what is Right Thought in concrete terms?
Obviously, a thought in which there is no suffering.
And what constitutes suffering, in our thought?
As the Buddha said: confusion, distraction, anger, hate, desire and lust.
We need to eliminate them.
But how?

Brothers, confusion and distraction, anger and hate, desire and lust can be overcome by practicing the Four Contemplations.

To overcome the confusion and distraction, practice the contemplation of breathing: it will clear your mind and increase the power of your concentration.
To overcome anger and hate, practice the contemplation of compassion: it will throw light on the causes of the anger and hate present in your mind and in the minds of those who have aroused them in you.
To overcome desire, practice the contemplation of impermanence: it will throw light on the beginning and end of all things.
To overcome lust, practice the contemplation of death: it will throw light on the decay of things. ( Vinayapitaka, Vibhanga Sutta )

Confusion, distraction, anger, hate, desire and lust obviously constitute negative thought.
But it is not enough to eliminate negative thought.
We must also construct positive thought.
What are positive thoughts?

Loving kindness, compassion, shared joy and non-attachment are wonderful, profound mental states.
By practicing them, you will become a source of vitality and happiness for all creatures. (Suttapitaka, Majjhima-Nikaya, Cularahulovada Sutta)

In a word Positive thought.

Right Thought therefore consists of the systematic elimination of negative thought and the systematic construction of positive thought.

Right Thought consists of the elimination of Negative thought and the construction of positive thought.