I sing in a small volunteer choir (12-15 people) in which we have women and men singing together on some parts. (Aside from the common tenor-shortage problem, sometimes we sing three-part songs, and lower altos and higher tenors end up together.) What techniques can we use, either individually or as a section, to make those voices blend better? Everyone's on pitch and (mostly) singing in the same register, e.g. we're all in head voice.
I have noticed that the blend "naturally" sounds better on some songs than on others; would doing some sort of analysis of those songs help, and if so what should I be looking at?