As i said before i am going through the steps you may consider when you are choosing your styles .
2.See if the garment is stained. In this case, it is double or quits. Either you are lucky and everything goes in the first wash or not! However, you can estimate your chances wondering if this is a discoloration (most annoying). Such situation happens often located in the same places: the neck, underarms, and hems. So check them systematically buying vintage.