You may know this already, but sometimes it helps to get a reminder. If you don't know this already, then you have learned something new today!
Never go to the grocery stores hungry. You will buy unplanned or unnecessary items, known as impulse buying. It is best to have eaten your meal or snack first, that way you go on a full stomach, and be less tempted to do some impulse buying.
A former car salesman informed me that when you are shopping for a vehicle, do the car shopping at the end of the month.
Hope these tips help or have been good reminders for you!