After leaving Sacre Coeur, it's time to peruse through Place du Tertre.  Continue west of the church on Rue du Mont-Cenis, and you can't miss it.  Yes it will be packed with tourist. Yes people will try to sell you things. But, you are already in the neighborhood so why not take a stroll around the block. Try to imagine what it must have been like back in the day, when artists would set up around the perimeter of the square just like you see in front of you. Dali, Renoir, and Picasso did live right around the corner afterall...