In person, I believe size definitely matters. Big is impressive. Small is easy to overlook. However, online, small originals sell much more quickly than larger works. Thus, I work in a wide range of size for different audiences. When choosing a size purely for personal preference, I like 18x24, 20x24, 24x30. Larger than that can be difficult to manage in my small studio. I have to wait for warm weather and work outside.