You can't carry a 908 cocked and locked.
Decocked with the safety on or off are the only two ways.
You can carry it cocked and off safe, but only a fool would.
Personally, when I carry my 915 is decocked and off safe. The heavy trigger pull is more than enough protection. It's exactly like a revolver.
As far as IWB, FIST #20 is my answer