Found some tricks that helped me to avoid overspending on grocery and entertainment categories in my personal budget.
The first one is accomplished by not taking a cart in supermarkets. I just take as much as I can carry in two hands. This has decreased the average check by almost half.
The second is a rule to have an outdoor party, park visits or whatever else falls in entertainment category - only once a month. Besides savings, it also helps to select a good party, because you think twice before "spending" your only chance :)
Here is another small one: remember indigenous people of America and don't exchange gold by useless stuff such as souvenirs, etc.
One more: don't take cash or credit card to a major purchase. When chosen and decided you still have a chance to cancel it when go outside to bring the money
And finally, revisit all recurring expenses on a regular basis: rent, mobile contract, bank fees - all these tend to change. One call can get you in a better position for the next months.
Have a fun