You get to know what you're looking at after a while. Had a guy bring a boa into the herp society meeting some time ago and asked what it was. I told him it was a Bci/Bcc cross. He asked how I could tell. *shrug* I just could. Later found out from the breeder I was right.
Another time we were offered a very nice boa at our local expo. Donnie called me over to look at the nice cross. I told him it wasn't a cross, but a pure Bci. He wasn't so sure... found out again, I was right.
It's hard to explain how to tell the difference. We have a cross here. I'll get pics of him so you can maybe see what I'm talking about...he is a Guyanan x Central American.
*edited to add* Pics:
