Make it warminf for the sutdents..
Make sure to always make it warming to new students, they always remeber their first day in school.
I think it is important to make their first day of class VERY interactive instead of all lecture. I play one of two games for them to get to know me: 2 truths and a lie (depending on the size of the class we can all do this or I break them up into smaller groups and the head "liar" presents)--or "I can do/have done something you can't do". In each case, I have the entire class stand up and don't allow them to sit down until they have gone. This is especially effective in game 2, as I am standing and I recite all the ingredients in a Big Mac--backwards and in under 10 seconds! Then I sit and encourage them to think of interesting things about themselves. I've had students break dance, or have been the runner up in a Miss American pagent...and nicknames are given in my 2 block English class that have lasted through graduation based on these games! Retention at its best!