The world's finest example of mass efficiency
Tokyo is a big city! Travel destinations are spread over a big geographical distance. There is no better way to get around the the metro. Don't be intimidated. If possible, avoid rush hour if you want some personal space. If traveling to multiple sites, get a a pass, there are 3. They make travel easier and more economical.
Ordered the 72hr passes to be delivered to our hotel on arrival
Excellent service - had passes delivered to our hotel as we had an early tour from Tokyo Station the next day after arriving. These really helped and saved money and time. Metro and Subway are great to use but the stations are vast and have many different exits so look out for signs and take into account of your station number exit or you will get lost. For the most part we did well, but there were a couple of times it was confusing. It was our first time and will definitely use these again as it was easy to move around and not worry about which line to use. They do not work on the JR lines but that didn't matter as we had that sorted out separately when visiting Kyoto and Mt Fuji. Subway and Metro are definitely cleaner but you do walk alot even in the stations to get to the many different lines.