I have a cigar box Guitar I hardly ever play but its a four string and I tuned it as One would a Ukulele.

the way I understand it a Ukulele is tuned as If starting at the fifth fret with the D,G,B and High E string.. so the Tuning should be G,C,E and A.

so, like starting at the A minor where you would normaly start at E minor on a guitar.

hope that helps.