Hit it as if you would hit any other gap ..
Land both wheels same time on the landing stairs ... momentum is your freind with stairs .. the faster you going the smoother it is ..
Biggest ive done is 11 - 10 ...
Scotty got a pic of it the other night ... As everyone above said .. Take it race style .. Low and fast .. no hucking unless you feel like a trip to the hospital .. Keep low fast .. make sure youve gapped things before .. example jumps .. Landing front wheel first or both wheels in a down position.
My Advice .. find something small .. then once your totally confident .. go knock yaself out ..i mean find a larger gap.. or set of stairs. ... But yeah in your case what your doing is good practice .. bunny hoping into a set of stairs and getting your wheel positions correct is good .. same concept as gapping a set. - Although ya gotta make sure you clear the gap .. Hartails are no different .. just as smooth in my experience on both a dually and hardtail .. Although be sure to clear the gap on a HT as they will buck your rear wheel up if you fail to clear it .. whereas a dually will allow you to be sloopy. Ive only done a couple of stair gaps .. The Top one is the largest 11 - 10 .. much bigger then what the photo looks like damm it... and the other was our first attempt .. Myself Ryan and Ty battled this bitch for ages .. Nothing hardcore though.