1) Stick To Your List: Don't look around. Instead, you should look straight ahead.
2) Stay to the Left: Everything to the right are their new items and items they want you to buy. If you go to the left, you won't get as distracted.
3) Avoid Free Chocolate Samples: If you indulge in something like chocolate, your inhibitions have lowered, so the next store you go into you're going to indulge more.