I use a vacuum cleaner with one of those crevice tools attached to the flexible hose to get out the major accumulations of dust and cobwebs inside the chassis, fans, slots, and other areas, I just stay away from touching the actual PCB and IC chips. I then use an approx. 2" paint brush with fairly stiff bristles to dust off the PCB and IC. I have used the vacuum cleaner on those areas, too, but it makes me a little nervous. Thus far, I have never had any zapping incidents.
Compressed air can force dust into crevices just as well as it can flush dust out of them. Vacuum cleaners pull the dust out rather than just pushing it around, and doesn't produce a cloud of dust that requires taking it outdoors to blow out. I used to spend $12 ~ $15 / month on that stuff, even buying bulk multipacks.