Although I get rid of clothes continually, I also thrift a lot and so I acquire them continuously as well. Plus I am also part of that continual swap circle and get offered things to look through. I don't want to sound like I always come to a quick decision about things that I take or acquire. Sometimes I do and in other cases I have things hanging around for a few years because I "intend" to wear them. About the only pattern I have is that I will wear many things right away and wear them a lot and they are new favorites but soon I am over it. I frequently change the style of what I am wearing, too, and that's the main reason I get rid of things. Pretty much everything I get rid of is in good to excellent condition. A few things that get worn, I do throw out. I like the advice not to donate anything that you would feel uncomfortable about offering face to face to a friend or colleague.
I will take the buttons off something if I really like them - I change the buttons on things quite often. Then I will still pass it along because my friend has a button stash and will sew some on in order to pass it along further. She's far more conscientious than I am. If it weren't like this, then I would probably just throw the buttonless garment away.
I don't donate any clothing myself to a thrift store. I hate to shop - but love clothing - so I limit my shopping to just a few nearby retail outlets and one current favorite thrift store and a few others sporadically. I prefer small thrift stores. So the last thing I want to do is see my own rejected clothing taking up the racks. I also don't have a car so I'm not going to trouble myself to go out of my way and make difficulty for myself. I won't launder the items, either. They go in whatever condition they're in - either unworn, freshly laundered or worn.
My clothes would last practically forever. I hand wash everything and don't put in the dryer. I have even been known to handwash coats.