Shadow boxing- practice your defensive moves and counters in front of the mirror then again on the bag. Then get yourself a pair of what they call Coach's Spar mitts (close enough) and a "body protector" (Ringside, Everlast, everybody makes these) and you can work with him in relative safety. You know, working specific moves and him perfoming them.. How ever you go about it, I would suggest never practicing defense without also practicing the counters. I've got some very worthwhile defense drills, such as very clear dirctions of how to do each move then lists like "left hand counters for a straight left lead" . Included are sidestepping and lipping etc.. I'm about done for today but tomorrow I can post these (may have to ask somebody how to do that) as they might prove helpful for a number of the people that have posted questions