Hang dry, but it's not a choice really. Small apartment so no room for a dryer. (Already the washing machine is half-sized.)

I always wash my gear as soon as I get to home from training, but sometime there can still be a whim of smell in the gi after hang drying. Nothing too bad, but I'd just like to be a dude whose gis smell fresh. :D I use some hypoallergenic washing detergent with only subtle aroma (which my wife prefers), never a softener.

I usually wash at 40 degrees (C) and tumble-dry at highest available (1500 rpm currently) then hang. And that goes for ALL my gear (including no-gi).
My gi's have been shrinking a lot... especially lately when I'm now up about 10 kg from when I bought most of them...

I always throw in some OdoBan in with my gear, then detergent and fabric softener and my stuff never smells. The great thing about OdoBan is that it is a disinfectant and sanitizer and kills 99.99% of germs.

I wash all my gi and no-gi gear in cold water with Tide detergent and a little bit of Oxi-Clean. Occasionally I'll add a little vinegar. I always hang dry all my gear unless I'm trying to shrink my gi.

After use, I soak my gi's in soapy water with vinegar over night and then I wash and dry them. Even throw in a fabric softener towelette. Can't stand the smell of a hang dried gi on me. It's good for other folks but I don't want it on me. Different strokes for different folks.

Cold water wash, with a little ammonia every third or forth time.
Hang dry unless I want to shrink it a bit when its new.
This goes for rash guards as well.

If the white ones get a little gray in some spots, I use a little stain remover or color safe bleach on the spots.

You can restore a white gi with one cup of color safe bleach in 3 gallons of water, in a 5 gallon bucket for 15 minutes and than immediately cold water wash.
Make sure the gi is moved around and gets completely soaked and submerged in the liquid before starting the clock.
Some people need to wear gloves around bleach.
It will make it bright white again, but it will fade colors after a few times of doing it, so keep the gi clean, so you don't have to do it very often.

You can also lay your gi out in bright sunlight for a day or two, and bleach it white that way. It's much slower but very even.

Sorry for not using the metric system, we are still primitive in the USA.

I have 10ish gis in rotation and I wash them allways as soon as possible after training in 30 degrees (C) and hang dry. For blue gis I use orchidea softener, black gis coconut and white flower softener. For white gis vanilla softener. I love smell like a little flower on the mat.

Lol