sterilized scalpel !! OR a brand new razor blade.. either way, don't use scissors.. you'll crush the stem, no matter how sharp they are... If done right, scissors probably will work no problem but avoid crushing the stem all together by using a razor blade.

Start cloning from the bottom and work your way up..

Also, when you cut the clone, put it in water and cut it again on a 45 degree angle so that there is no air inside the stem.... do this while it's underwater then go from there to your rooting hormone..

Gel's work alot better than powders.. they coat the stems a bit better and generally have a higher IBA % (eg. Rootech gel has a .55% IBA and Stimroot #1 has a .11% IBA)

IBA = Indole-3-butyric_acid the active ingredient in rooting hormones.
Indole-3-butyric acid - Wikipedia, the free encyclopedia
Auxin - Wikipedia, the free encyclopedia

DO NOT USE anything with a higher IBA of like .60% because you can potentially poison the cutting.. usually the higher the IBA the more it's meant for hard wood cuttings... like.. trees..

Hope this helps.
Bob.:stoned: