Here are my 10 tips.

1. Get a Suica or Pasmo card.

2. Sign up for international service with your home country phone company as a backup but then buy a data SIM in Japan. If you have Skype premium or something similar you can make all the calls you want with just the data SIM.

3. Sign up for and load the Uber app before you go. Download the Japan taxi app also if you can. You can get a Tokyo phone number with Skype premium if you need it for the taxi app.

4. Walk a lot. Central Tokyo is pretty compact.

5. Be prepared for rain and/or hot weather depending on when you go. Ultra lightweight rain jacket/pants are a good idea.

6. The trains/subways are really easy to use. Try them early in your trip. Hyperdia a good app for any kind of extended trip.

7. Don't be afraid to wander into shops/restaurants. No one bites. Get comfortable doing this your first day. Don't eat anything at your hotel.

8. Pack light.

9. Try to meet Japanese people.

10. Learn Japanese before you go.