Here's a little tutorial on the Horizontal stitch used in the HBDS (as i've been doing it, any how!).  i've never made a tutorial, so if it sucks really badly, i'm sorry!  let me know how i can make it better, and i'll do my damnedest to oblige you.   For the tutorial, i've used the following pattern:  _|_|_|_||O|=|=|=|_|_|_ 

Step1:  knit first 3 stitches, the next stitch will start the horizontal stitch (HS).

Step 2:  in the next stitch (the fourth for our purpose) knit f & b.  The stitch knitted in back is the 1st HS.

Step 3:  Reverse the orientation of the 1st stitch on the LH needle.

Step 4:  slip the 1st stitch on the RH needles to the LH needle.  Knit the 2nd stitch on the LH needle (the one that you reversed in step 3) TBL, then knit the 1st stitch. Drop both worked stitch from LH needle.

Step 5:  repeat steps 3 and 4 for the required number of HS charted.

Step 6:  to finish the run of HS, k2tog (instead of steps 3 and 4) on the very last HS stitch.

Results (pic #7):  here is what the above chart looks like, all knit up.