Sustainability - T-Shirt

Sustainability describes good ressource management. Everytime that I waste ressources, I don't act sustainable.

And this applies to so many aspects of live!
Textiles for example. Even though I have no idea how a t-shirt is produced, some steps are probably:
► Planting the material for a t-shirt,
► harvest,
► process,
► print the occasional logo or motive,
► and then transport.

I guess there are even more steps, especially if the shirt is ordered online and not bought localy; this is also results in package waste and even more transport. So do I really need more T-Shirts? And where are all the shirts that have been produced already? Is it realy reasonable to have so many clothes that just lie around in the closet? I have never bought anything from a second-hand shop...I should change that!
Recently there has been a lot of talk about "fashion lending". I'd probably pay a monthly fee for some clothes that I bring back at the end of the month. Pretty interesting system, even though I don't really care for fashion. There are a lot of people who do.

• How often do you shop for clothes?