Craft is about details. The rounded corners and smooth edges. Making sure the pixels line up and nothing is out of place. Precision is what creates energy and movement in a design. Users may not notice in a conscious way, but they will feel the difference between getting the details right and having bits out of place.
Error messages are always well considered.
Transitions between screens or pages are smooth, and sound is used to reinforce the action and give subtle reinforcement about what's happening. Craft is about deciding to do less, if it means the quality bar for what is in the product is outstanding. Doing less facilitates greater focus, greater quality, and greater design. Our industry and culture doesn't promote these things as much as it should, but your users will always notice and respond if you give it to them. Write in and tell me about it.