Sometimes it takes just one repeat, sometimes hundred to become lucid ^^
The most important thing is to really feel the mantra, not just repeating the words but truly feel the intention and visualize a bit maybe. The idea behind it is important, not the sound of the words itself.
And in mantras never use future time like "I will" or "I am going to". Use present only just like it's happening right now. Your subconscious reacts better like that :-)