Never let users guess what's the next step on your user journey.
Have in mind that conversions might be low because people are afraid to press a button.
A strong message (like "Reserve") adds stress and makes people wonder whether they'll be charged or not.
Align Uneven Elements
In many cases, you have to align uneven in size elements. Even if you set the spacing between the elements to be the same, the visual result seems off.
Fallback for Transparent Avatars 1
Many platforms (like Twitter) allow PNG avatars that can cause UI inconsistencies
Fallback for Transparent Avatars 2
Round images usually look weird when they're included in a card with a small border-radius.