Depending on ontext I'd put that lower one either on the open B string or on the 4th fret of the G string. Or maybe 9th fret of the D, etc. Depending on the fingerings of surrounding notes.

That higher one, I'd put on the seventh fret of the E string, since anywhere else and you'd be way way up on the neck. I mean, you could put it at the 12th fret on the B string, of course...