Most people always have the KEYs set to FILES, LOAD", SAVE", LIST ERR, RUN, since you can't change the defaults in the settings.
Obviously, this is not a very good selection of commands, since LOAD", SAVE", and FILES are obsolete, and RUN is only used to run slots 1, 2, and 3, but it doesn't have a space after it, so you have to type a space AND the slot you want.
If you could change the default keys, what would you change them to?
remember that you can use CHR$(13) at the end to make it automatically run when pressed (so you don't need to press enter)
I would set them to:
1: (nothing, since I always press this one accidentally)
2: "ACLS"
3: "CONT"
4: "LIST ERR"+CHR$(13)
5: "RUN "