I use -5, D DU UDU

D D UUD DDU (as seen from UkuHaley's video)

I play the verses as C Em F and use DDU UDU

I use +2 and the strumming pattern "D D D D D D DUDU" with a mute between each D strum (like in TenThumbs Productions' tutorial on youtube)

I like either using "D D x" or using "DUx D x" as strumming patterns, and -4 is easier and sounds great!