Repetitions are extremely useful for the purpose, especially if you are using conversational hypnosis for persuasion. The problem is that often repetitions are too obvious.
For this reason, you have to make them more covert. One tactic is to pace and lead using repetitions. For instance, you can say, “You want to the movies. You went to the movies and you saw movie X” and so on.
This pattern for influencing the subconscious mind may seem a bit weird when it is written, but if you pronounce it with the right tone of voice, you will see that it is perfectly logical and the person will accept it. This repetition in pacing allows for getting the person into trance more easily.
Once you have made the person imagine the benefit of doing what you want. You can readily ask him, “How happy are you about getting this benefit?” This question with presupposition really works, especially if you have made the person feel happy about the benefit in the first place.
Another great pattern allows you to use repetitions for reminding the person to do the thing you want. You can readily say, “Are you still thinking about doing X?” This question is closed so you have to mention the benefit the person will get from doing X straight away.
The whole pattern will be something like, “Are you still thinking about doing X? Doing X will bring you benefits Y and Z.”
In general, using questions is particularly effective for influencing the subconscious mind. That is why you may want to focus on using patterns containing questions more often.