What are good ways to divide my attention between my twins?

Depends on age. Early on in life it is mainly a matter of juggling feeds, wakings and touchy feely time. Later on it would be a good idea to occasionally have someone watch one of the twins while you or your partner spends time with the other twin.
Mom/Dad each get one. After each daytime feeding, mom should spend some time with one twin while dad spends time with the other twin. After the next feeding, the parents can switch twins. This way, each twin gets to spend some one-on-one time with each parent.