Food
Eat breakfast at home, a good lunch out and avoid swanky diners. Most restaurants charge less during lunch time and serve many delectable dishes.
Eat light for dinner, besides it is a good idea to eat lighter before bed so you can get a good night’s sleep.
Avoid junk food traps at tourist spots, they are usually delicious but overpriced.
Drink plenty of water while traveling, becoming dehydrated is the last thing you want during travel. One fun idea is to have a picnic with sandwiches or whatever you like from a grocery store (which is cheaper than restaurants).
Lodging
Choose your lodging wisely and book ahead when possible. Sometimes you can get really good deals by booking online well in advance of the trip.
The other thing to consider when choosing lodging is the area it is located in; avoid popular tourist areas because they tend to be more expensive and are harder to get in and out of.
The other reason you want to find accommodations away from touristy locations is that you will be less tempted to spontaneously buy something.
Always rent apartments over paying for hotels, especially for families, it’s so much cheaper and you can make food at home if needed.