I've seen professional perfomers do a series of card effects using a different selected card for each effect. It's the usual thing to do.
But it's a chore to have to remember a card.
I've started using the selected card from my first effect in following tricks. So, for example, I may have a card selected, find the wrong card and change that into the selected card. Then I might do the Card in Pocket but I use the same selected card. So there's not another card for a spectator to remember.
(Maybe that's why the Ambitious Card" is so successful.)