Actually next time just try talking to it to complete the task.

I use Google's voice recognition a ton when on my motorcycle with a Bluetooth helmet. I've gotten in the habit of just trying things and to my surprise many have worked.

Play/pause music, mute/unmute voice navigation, ask how long until my next turn, ask it to navigate to somewhere else, call/text/send a hangouts message to a contact by their nickname, play a specific band or album of music, etc...