I have 9 windows with mini blinds on them in my house, and the way dust collects around here, they are a pain to keep clean. Taking them down and cleaning them in the tub with soap and water, or taking them outside and hosing them off, are probably the most thorough ways to get them spic and span, but if they are just dusty and not grimy, I usually prefer to just vacuum them with a brush attachment.
However, my new favorite way to give them a once over to get the dust bunnies off, is to use a paintbrush to easily get in all the nooks and crannies, and “brush” the dust off. It’s not as taxing as using the vacuum, although you still need to be sure and wipe up the dust that falls off with a damp cloth or vacuum it up.
Start at the top and work your way down, so you’re not undoing what you just dusted, and then admire your work!