Perhaps this is a simple matter that I should be embarrassed not to know (which I am even if it isn't because I need to learn hilchos b'rachos better and always forget to look this question up) but....:
If I am drinking beverage with my meal and have decided I am finished eating but would like to continue drinking what is the proper procedure? Should I wait to bentch (say birchas hamazon) until I have finished drinking, bentch and continue drinking with a berachah achronah as necessary, bentch make another berachah (l'vatalla?) and then a berachah achronah, or otherwise?
(Of course I am not asking l'maaseh, but the answer will hopefully point me in the right direction, and remind me to study the topic from the sources and ask any relevant sheilos.)