I use a manual plastic squeeze bulb to get the worst off (if it's been a while) then finish it with a few blasts from compressed air held some distance away.
I can't imagine using a leaf blower. I mean I'm sure it works and all, but using a leaf blower just to dust out the pc feels a bit excessive. I guess it's "free" tho, assuming you own one already. But cans of air aren't that bad and you don't need a lot. It lasts a while.
Even better is having the PC in a room where dust collection isn't very severe to begin with. And not having it rest on the floor/carpet.
Also, dustfilters in the case does help a bit, means you clean filters instead of components.
I might be entirely wrong here, but I'll blame my father for it; It should be fine to use a vacuum cleaner for cleaning your PC, just make sure that you somehow lower the air velocity. If you can lower the vacuums speed you lower the risk of discharges. I usually put it at the lowest setting and use a plastic bottle cap with a hole that I've threaded a 5mm plastic tube through.
Edited by Azdeus, 24 July 2018 - 01:41 PM.