In an itemize-like environment, nodes (i.e., `\item's) may be inserted using C-c LFD.
Command: LaTeX-insert-item
(C-c LFD) Close the current item, move to the next line and insert an appropriate `\item' for the current environment. That is, `itemize' and `enumerate' will have `\item ' inserted, while `description' will have `\item[]' inserted.