You can also download maps for offline navigation using apps like City Maps 2Go and OsmAnd.
Take a picture of your fridge or pantry before you go to the store to remember which groceries you need to buy.
If you lose your phone a lot, change the background to your name and emergency contact information in order to keep track of it if it gets lost.
Keep travel information in one place -- like a note on your phone or an app like TripIt -- so you don't have to waste time or data searching for it.
In order to get the perfect travel shot, hold down the photo capture button to take a bunch of pictures all at once.
If you have a poor signal, put your phone on airplane mode and then turn airplane mode off. The phone will then connect to the nearest cell tower.
Bring a power strip with you in case you run out of outlets to charge your phone in the hotel or at the airport.
Roll down your car windows if you don't have a signal -- it can go a long way to helping you stay connected.