Excerpt from my latest Sasstrology article (please leave comments on the Sasstrology site):
"Each sign has a distinct set of characteristics (Scorpios are intense, Leos love attention). Planets express their energies through the signs, and the signs describe how planets express their energies. But what happens when you have a planet on the cusp? For example, your Sun is at 29 degrees Gemini, and the next degree is 0 degrees Cancer. Do you express your ego (Sun) as a Gemini, or are you also influenced by Cancer?"