here is another great tip concerning the express keys..
There are all kinds of normal things you can select, then there are some you have to set "Keystrokes" shortcuts for.
Navigator for example. (in windows this has no preset keyboard command i'm aware of. so I made mine Alt+F4, then set express key for it.)
First, in PS, go to edit, then "keboard shortcuts".
here you can look through all of the shortcuts that are pre-made, modify and/or add them so you can use express keys for your frequent things.
(such as ctrl+shift+I for invert selection, you can modify it to alt+F9 then set that as a custom express key function from the wacom settings. the reason for this is the wacom software dont see "shift" as the same type of modifier, it only caps the letters in the command, so it don't work the same as pressing shift Ctrl I.)
go into the start menu (or where your programs are) and select the wacom tablet properties, then you can select from the tabs which tool, and which buttons you want to mod there.
If you need any specific hepl with these settings, post in here.
Have fun and enjoy