I also check if the lenses have any blue light filter or anti-reflection coating. Whenever I find something that actually works well, I tend to reorder it later. If you sit in front of a screen for many hours, these small features make a difference. For fashion and clothing I pay attention to fabric thickness and stitching details. If buyers say the item runs small or large, I always adjust my choice accordingly. The same is true for metal versus acetate frames for glasses.
Smaller shops can be surprisingly friendly if they care about repeat customers. If they ignore basic questions or reply with copy pasted text, I become suspicious. It saves a lot of trial and error for everyone else. For example, I compared cotton, polyester and mixed fabrics for similar clothing items. I do not trust only the star rating, I like to see detailed photos and longer comments. Each material has advantages and disadvantages depending on season and activity.