Ramana Maharshi shares the following wisdom about meditation and overcoming thoughts:
M: In meditating on an object whether concrete or abstract you are destroying the sense of oneness and creating duality.
D: What meditation would help me?
M: No meditation on any kind of object is helpful. You must learn to realize that the subject and object are one. In meditating on an object whether concrete or abstract you are destroying the sense of oneness and creating duality. Meditate on what you are in reality… you will find…
M: You will discover. It is not for me to say what an individual experience would be. It would reveal itself. Hold on to it.
D: But you have often said that one must reject other thoughts when he begins the quest, but the thoughts are endless; if one thought is rejected, another comes and there seems to be no end at all
M: I do not say that you must go on rejecting thoughts. If you cling to yourself, say the I-thought, and when your interest keeps you to that single idea, other thoughts get rejected, automatically they vanish.
D: And so rejection of thoughts is not necessary?
M: No. It may be necessary for a time or for some. You fancy that there is no end if one goes on rejecting every thought when it rises. No. There is an end. If you are vigilant, and make a stern effort to reject every thought when it rises, you will soon find that you are going deeper and deeper into your own inner Self, where there is no need for your effort to reject the thoughts. The effort is sublimated in just awareness of the Self.
D: Then it is possible to be without effort!
M: Not only that, it is impossible for you to make an effort beyond a certain extent.
D: I want to be further enlightened. Should I try to make no effort at all?
M: Here it is impossible for you to be without effort. When you go deeper, it is impossible for you to make any effort.