Spot on information here guys! All very well said...
I just wanted to add that I too have taken cuts with no nodes whatsoever below the surface. To get them to root nicely, I "scarify" using a #11 scalpel. I very carefully "shave" off the stems outer layer exposing the cambium. The cambium is where the roots begin to develop which is why a node below the surface roots the quickest. The cells of the cambium closest to the node have the highest concentration of hormones as well which facilitates root growth.
I have also experimented with "splitting" the stem up the middle for about 1/2". The concept is the same, exposing the cambium for more plentiful root development.

Peace, E1

I have to keep my mothers and veggies height in check so when I trim them, I take clones from the best leftover tops and branches and place in a glass of water.

At the last node, I (carefully) break, from the top of the intersection and peel, the lowest leaf down to the cut as my scarification. I remove large fans and trim some of the mid sized leaves to slow the loss of water, then back in the water.

I use no gel or other hormones but I am using an Aero Garden. I poke a hole three-quarters (of the 'plug' length) into the Aero 'plug' so the clone will slide in (these things are made for seeds). Fill the Aero with ph 5.9 and Thrive Alive B-1 and pre-soak 'plugs'.

When everything is ready, I take a clone from the water and re-cut the end ten millimeters below the node on a forty-five and insert into plug and into Aero. I now try to ignore for a week. This usually returns seven out of seven clones.

As far as two nodes below, sometimes I guess, but definitely two or more above. My two cents worth...

I have always taken my clones from where ever on the plant, but usually the cuttings I take are the ones closet to the soil, as I take my cuttings when I am shaving their legs for flowering. I don't know that I have ever taken a clone that was below the soil surface.

wow someone actually found a good use for an aerogarden, I'm amazed, pretty expensive cloner though.

Yeah Rebel Dawg, it's sweet for cloning, takes up little space, easy to maintain, self contained, etc. and it would have been expensive had I bought it. I got it as a gift from a friend that was not using it. Great price on my budget.

I have a diy, five gallon, nineteen hole aero cloner that uses those one and three-quarter inch diameter rubber plugs but don't use it any more as I kept getting too many clones for my perpetual grow. I only need a few clones every two weeks and I hated destroying all those extra babies.

There is a bulb out in the Aerogarden I need to replace that but it's still cranking em out out on the one good bulb.