Sites like Warby Parker will send you a bunch of frames to try on for free so you can see how they look.
And I find sites like Zenni are so cheap that it's worth taking the risk: an ugly pair can go in the car /gym bag / work desk for if I lose a contact lens.
Every time I change glasses I try at least 20 frames, more likely 40 frames, before finding anything close to acceptable. Something that looks fine on a shelf most often looks ridiculous on my face. Can't imagine ordering online.
And I find sites like Zenni are so cheap that it's worth taking the risk: an ugly pair can go in the car /gym bag / work desk for if I lose a contact lens.