I find that modulating up to the next key works very well to 'lift' a song especially in songs that may have a relatively simple chords progression ... I do this in songs like:
Cab Driver
My Darling Clementine (Bobby darin version)
L-O-V-E (Nat King Cole)
Michael Row The Boat Ashore
If I Had A Hammer
Mack The Knife (OF COURSE)... and others ...