This is a bit more advanced but I find it really useful. Open a terminal window and type in or copy paste the following and press enter:
defaults write com.apple.dock persistent-others -array-add '{ "tile-data" = { "list-type" = 1; }; "tile-type" = "recents-tile"; }'
Then type:
killall Dock
to restart your Dock. You will have a new stack item on your dock allowing you to access the ten most recent applications.
