Some thrift clothing can last a long time depending fabric it made with . I would purchase name brands like Ann Taylor loft, Express, the Gap, Talbots, Chico’s because they are quality brands and the clothing may be more resistant to wear and tear of the washing machine.
Purchase clothing that is washable in laundry washing machine not dry clean only articles.
There are ways to make thrift clothing last longer by,
Picking up nonbranded and branded clothing first make sure its washable and not dry clean only.
Wash in cold only, hot water will wear out clothing faster in wash.
Air dry clothing instead of using dryer
Mend any holes it may have by sewing
Shave off the lint off clothing with clothes shaver
Gently steam the clothing instead of ironing
Hang your clothes to air them out daily
Use Oxiclean to get tough stains out
Spray with white vinegar to get out smells
Try not to wash clothing often to keep them from wearing out.
In summary using these ten suggestions can help to keep thrift store clothing from wearing out too soon.
But keep in mind that the clothing at the thrift has been proven to be strong because they are in resellable condition. Some fabrics can be sustainable depending upon the brand. With proper care clothing can last 15 years or more.