I remember when I was preparing myself to a first presentation in english, my a friend told me the following expression to be used when I had a chance to give/exchange my business card to someome : You never know when we might be able to collaborate toghether sometime. So , used it a lot of times and it made me feel confident  , so I have to say it was GREAT!!!

And about you ?

Regards,

Giva

Hi everybody, It happens very often to talk about something that is not main topic of discussion or presentation. Then, this expression will be useful when you wanna turn back to main topic. “We are getting a bit off-track here, we’d better get back to the topic of ....”. One more common manner when I need attention from audience is "Now, if you turn your attention to (screen, monitor, handsout...)" You never oder something to audience, be in generous manner.