A small correction in the comments about slack key--there are hundreds of tunings--no standard one--it was once not uncommon for players to keep their tunings secret, but I think that is not the case anymore--

They like to work from those big fat airy chords. like a G13, for instance--
(here's how to play it on a regular tuning)

3-x-3-2-0-1-0

Try a playing a nice, slow, thumb arpeggio, followed by an up-down-updown-updown pattern with your index finger and you'll get a feeling for it--If you like it, tune your strings to

G-B-F-A-C-E

Then fool around a bit and see what you come up with--