Okay so chakra molding, channeling and projection?? Huh...
I thought for a while, before coming up with an answer. I wanted to go into as much as details as possible and hence decided to make it a little bit lengthy, while adding few extra points.
Genjutsu, just like many other techniques is a part of ninja techniques. Only difference is, the effects are illusionary, still it requires chakra and handseals, extensively. Chakra is made up of physical and spiritual energy. The most notable thing about genjutsu is, it requires me to produce illusionary effects and not real once and hence is more associated with yin aspect of chakra and hence associated with spiritual energy more, this is something that I need to take care while molding process, but still I need to mold both physical and spiritual energy both, to give 'form to my imagination'.
Another, most important thing which needs to be taken into consideration is, to put ninja into genjutsu, one needs to channel chakra into his brain and confuse his senses, this is where the tricky part comes, as it requires intelligence and skill. Skill to confuse his senses and chakra control to channel chakra perfectly into his brain, so that he won't be able to notice this process. This higher amount of chakra control is associated with handseals and hence almost all genjutsus require handseals. The control over chakra can also be obtained without using handseals, but it requires special skills, such as sound genjutsus(which put opponent into genjutsu instantaneously due to amazing speed of sound) and also Sharingan genjutsus, which only need eye contact. These type of techniques, make them much more deadly.
Another important aspect that we need to take into consideration is, chakra never flows physically out of your body, but is projected and hence your chakra system may get disturb and hence you can't see it coming, you can figure out that you are in genjutsu, only after being put into one. These important aspects of genjutsu make it difficult to counter, if used properly.
That was enough, I thought to myself. I had tried my best to illustrate the stuff. The only thing that was left was listening to the verdict of my sensei.
So I just wait nervously, waiting for him, to respond.