Also, make sure all of your fans are dust free as possible
Certainly a good recommendation.
Another reminder is to clean the fine mesh "filter screen" in front of the front intake fan on better cases periodically. This is where dust from room air gets largely "filtered out" so that it doesn't make its way into the interior of the machine. That's great, of course, but it now just accumulates on this "filter screen" instead of getting inside the case. Still needs to be cleaned out, periodically.
My AcoustiCase has a washable/removable "filter screen" protecting the intake fan for exactly this reason.
use a can of compressed air to clean 'em off
My own personal feeling about this is to NOT use this "blown air" approach to cleaning things like fans, motherboard, case interiors, etc. All you're going to do is BLOW the accumulated dust up into the air around it in a big cloud, and then the dust has to settle again somewhere anyway... either right back inside the case, or on your floor or room, or somewhere.
I've always preferred to use a vacuum instead... i.e. the "sucked air" approach.
I normally use the round upholstery brush (?) attachment, which not only is part of the vacuum's "sucking" action but you can use it to brush the surfaces you're trying to vacuum clean of dust and not do any harm (just be careful, of course). This works on the motherboard and case interior and interior surfaces, and also on the fans.
For "tight squeezes" I may also use the drapery (?) attachment which is kind of a plastic cone with a narrow slit at the end. This can get between expansion cards, and other deep corners of the case, and suck up loose accumulated dust and debris. It has no ability to "brush" dust loose of course, but it's effective.
Anyway, I prefer to vacuum the dust out of my case interior and fans, rather than to blow it all over the place with compressed air (or the vacuum cleaner hose plugged into the "BLOW" hole).
One word of warning about using vacuum cleaners: they should never be powered up while too close to electronic devices that have magnetically-sensitive components in them. The magnetic field generated by the startup of the vacuum cleaner's motor can do significant harm to things like old CRT monitor screens (including old CRT TV's) which then need to be de-gaussed to eliminate the "rainbow flares" stemming from these magnetic fields. Fortunately, newer CRT TV's all included built-in de-gausser circuitry to do exactly this every time the set is powered on.
But the magnetic field from the startup of the vacuum cleaner can also affect computers in their magnetically-sensitive components, such as the contents of the hard drives, etc. That's also why desktop speakers intended for computer use are (or should be) "magnetically shielded" so that you can put them right next to your computer and/or CRT monitor and not cause any magnetic impact from the magnets in the speaker enclosure.
Maybe I'm over paranoid about this, but I always power on my vacuum at the other corner of the room, far away from my HDTV and computer.
