Which card first
Short stays: ICOCA or a compatible phone wallet. PiTaPa post-pay needs screening — most visitors skip it. Top up at stations and combini; not every machine takes overseas cards.
When to add a day pass
Four-plus city-bus rides and almost no rail: city-bus day pass. Dense subway plus bus: subway+bus pass. If you ride JR Sagano, Keihan or Hankyu: skip the bus pass and pay ICOCA by ride.
Do not mix Osaka passes
Osaka Metro day passes and many Osaka tourist tickets exclude Kyoto city buses and Kyoto subway. Day-trips from Umeda/Namba still tap ICOCA on JR, Hankyu or Keihan.