Make it a habit to check which exit you want at subway/train stations and have a general idea of which way to turn. This will save you time and hopefully result in not getting lost as often.

Use your indoor voice in public, especially while on public transit. It might take a while to notice that the overall voice level is quite low. Unfortunately, you might notice you've been speaking too loudly when you hear other foreigners, not because the language may sound familiar but because the entire car is getting a free foreign language lesson.

Carry some cash and a coin wallet. Temple entrances take cash. Street food vendors often take cash and most Japanese people don't walk and eat at the same time. You can use passmo/suica at the combini and this reduces extra change (some 100 yen change is usually handy while too much change is heavy).