The tag decides the washer or the dry cleaner.
Read the Label Before the Curtains Come Down
How to clean curtains and blinds safely, and why the tag decides the method.

Curtains and blinds collect dust that floats down onto everything below them, and most of it goes unnoticed until the light hits it at just the right angle.
None of that calls for taking every curtain down at once. It calls for checking the label first, since the fabric decides the method.
Check the care label first

Look at the small care label sewn into the curtain's side seam or hem for a washing symbol or instructions.
Why? Heavy, lined, or blackout curtains often need a dry cleaner, while lighter cotton or polyester panels are usually machine washable. Guessing can shrink or warp a lined curtain.
Vacuum or shake out dust first
Vacuum curtains with a soft brush attachment, or take them outside and shake them out, before washing.
Why? Loose dust turns into a paste once it's wet, and shaking or vacuuming it out first keeps the fabric from getting harder to clean.
Wash on cold and gentle if the label allows it

If the label allows machine washing, use cold water and a gentle cycle, and skip the bleach.
Why? Hot water and a regular cycle can shrink curtain fabric or fade its color, especially anything with a printed pattern.
Dust blinds slat by slat, closed then open

Close the blinds and wipe each slat with a microfiber duster, then open them and wipe the other side.
Why? Closing the slats first gives you a flat surface to catch dust in one pass, instead of chasing it around an angled slat.
Spot clean blinds, don't soak them

Wipe a stained spot on a blind with a cloth dampened in a little water and mild soap, rather than soaking the whole blind.
Why? Wood and faux-wood blinds can warp or swell if they get too wet, and fabric blinds can develop water spots that are harder to remove than the original mark.
If today's a low-energy day
Just dust the blinds today. That's enough for now.
The larger lesson
Curtains and blinds both reward the same habit: a light, regular pass with a duster does more than an occasional deep wash ever will.

A quick weekly dust keeps curtains and blinds from ever needing a deep clean.
