Watch the Combining Accents online guitar lesson by Jeff McErlain from Blues Survival Guide: Rhythm Edition
In this exercise I am mixing up all the elements we discussed so far to provide us with a classic blues rhythm that you can get tons of mileage out of. It is important to keep the right hand wrist loose when playing this stuff. A stiff tight wrist makes it impossible to play properly. Hold the pick firmly enough that it doesn't fly out of your hand but not so firmly that it interferes with the feel. I suggest watching guys like SRV and Robben Ford do this and see how effortless the motion it. I HIGHLY recommend TrueFire's Robben Ford's Blues Revolution course for some amazing insights into this subject.