Start with a subject you care about, look for what the artwork does with it, then choose the garment. A good graphic should still reward your attention after the first glance.
An artwork can have more than one garment edition. Compare the actual base, placement and product details instead of treating the illustration as the whole order.
A familiar object becomes more interesting when the image gives it a problem. Follow the fish that cannot fit, the tea that refuses to settle and the collectible that takes itself very seriously.
Different images answer different questions. The artwork shows the graphic. A campaign scene explores its mood. The selected product tells you which garment, colour and size you are ordering.