This is Dave Vick, IATSE #274 Master Carpenter, Flyman and Rigger.

We thank Dave for his contribution to our site. 

"These knots brought to you courtesy of a tattooed rigger-type guy on the flyrail".
 Rigger Dave Vick
 The snub is tied with 5'-6' lengths of 1/4"-5/16" line, with an eye either tied or spliced in one end. I prefer New England Ropes' Sta-Set for overall wear resistance and breaking strength (a throwback to my sailing days).  
 I also prefer spliced eyes to knotted ones, because they're stronger and don't weaken the line. You can buy lines pre-spliced, or get a splicing fid & learn to do it yourself; it's actually quite simple. Yes, I do my own.  Snub Knot, Step 2
 Begin by choking the line around the rail, with the working part of the line coming up from behind & through the eye.  Snubbing Knot, Step 3
 Take a turn around both counterweight lines with the snubline, passing it underneath itself as it comes back around - as if you were beginning a clove hitch.  Snubbing Knot, Step 4
 Laying the line *on top of* the first wrap, take another wrap. Be sure to pass the second wrap underneath the line coming up from the rail as before. Pull up on the working end to wedge it firmly under the line coming up.  Snubbing Knot, Step 5
Continue taking wraps in the same fashion, pulling tightly as you go. The finished snub should have 4-5 full turns, or approx. the same height in turns as the width of both ropes that you're snubbing. This is the main working part of the snub.  Snubbing Knot, Step 6
Once the turns are tight & secure, tie off the end of the line above the snub wrapping with a clove hitch. This doesn't contribute to the snub's working friction much; it's primarily to keep the end from dropping below the wraps, which would cause them to undo themselves. By keeping the end up & tight, the snub remains secure indefinitely.  Snubbing Knot, Step 7
...And there you have it!  Snubbing Knot, Step 8