This may seem simple, but it should not be overlooked. Find out where your English Language Learners are from. Show a genuine interest in their origins. All Spanish speakers are NOT from Mexico , and you can really hurt your relationship with a Honduran student (for example) by assuming he is from Mexico .
I usually frame the question something like, “Where is your family from?” This avoids awkwardness with students who were born in the U.S and whose parents are immigrants.
More of our ELLs are from Mexico than anywhere else, but they are from numerous different states (Mexico is divided into 31 states and a Federal District.) and I always ask them what state they are from.
If you know something about their country/state, tell them – they will be impressed and you will be building a bond. If you don’t know anything, ask them to point it out on a map and ask some questions.
Recent immigrants especially enjoy looking up their home towns in Google Images or Google Maps. If I have a few minutes to spare in the classroom, we do this together and project the image. I tell the class, “This is Jorge’s home town.” The ensuing conversation really builds bridges between immigrant and “native” students.