What Jason says is about it. You won't get 100% success, especially if you are just starting. Though in the beginning you might be more prone to micro-managing and have better success. Or not.
To me the two biggest 'enemies' also are heat and too high moisture, and if these happen at the same time your cuttings most likely may not make it.
I get nervous when the temps start to get over 75*F. About 2 weeks ago I had some fresh cuttings of two really good varieties get into the mid 80* and they are not prospering. Next time it gets that hot I'll put them in the wine cooler/cheese cave at 55* during the heat of day if necessary.
Too moist a mix is also a problem. Mix that is barely damp is important, and then not watering cuttings till necessary. I don't have a humidity meter, but since it's very dry here over the summer, I will use spray bottles when 'necessary'. Hard to explain when that is - guess it's gardener's instinct. In other words, I can tell by looking.
In summer I don't much worry about light since the days are long, but in winter, after cuttings put out new leaves, I'll supply extra light via florescents.
Good luck with your cuttings. It is a great deal of fun. :)