I was taught a comprehensive mental check list years ago which still seems to work fine. Various complexities have been added to it but they all seem to be able to be fitted into the rhythm of the checks.
The important thing with mental checks is if you are interrupted, start again from the beginning.
I personally find trying to use a check list is more disruptive than the mental method.
With an unfamiliar airplane, a checklist is definitely required until its pecularities are firmly slotted into the mental routine.