Read the seller's feedback. Any percentage under 98% is weak to poor.
Look at the Detailed Seller Ratings. Watch for low marks (under 4.5 stars) in communication and description.
As noted, look for an unusually high number of identical garments, unless you can be assured the seller has a brick and mortar business in the same field.
Don't buy directly from Asia. Asian manufacturers sell to the brand, and the brand sells to retailers. Direct sales from Asia are either knockoffs, seconds or total counterfeits. Quality and sizing will be erratic.