I've struggled with noticing thoughts arise for a while, but I've been reading the Ayya Khema book "Visible Here & Now", and in it she mentions what I believe are called (if I remember correctly) the four right efforts. These are:
1. Not allowing an unwholesome thought to arise
2. Replacing an arisen unwholesome thought with a wholesome one
3. Allowing an unarisen wholesome thought to arise
4. Expanding upon an already arisen wholesome thought
I hope I got that right, if I didn't then someone please correct me... Anyway, she elaborates on this point by saying that feeling comes before thought, so if we focus on feeling we can feel whether or not a thought will be wholesome or unwholesome before it arises and thus decide beforehand whether to think it or not. I've been practicing this and it's allowed me to get in front of thinking, so to say. Anyway, I hope that helps.
"The heart of the path is quite easy. There’s no need to explain anything at length. Let go of love and hate and let things be. That’s all that I do in my own practice." - Ajahn Chah