Priests and bishops bless with the fingers of the right hand held in the ICXC arrangement; laymen bless with the fingers arranged as if one is crossing oneself, as Basil320 said. Laymen can certainly bless their children, their loved ones, their food before eating, even the steering wheel of their car before embarking on a journey.
The Slavs have a beautiful custom when they marry. The couple obtains a matched pair of icons, one of Christ, one of the Mother of God, some time before their wedding day. These icons are blessed in church, then each icon is taken home: the Christ icon by the future groom, the Mother of God icon by the future bride. On the day of the wedding, before they each leave the house to go to the church, the bride and groom are blessed with the respective icon by their parent/s. The icon is passed crosswise over the bride or groom, following the same movement as one would cross oneself. The bride or groom then venerates the icon. The icons are brought to the church, and are placed on an icon stand in a prominent position for the duration of the wedding ceremony. At the end of the service, after the customary "words of wisdom" from the priest, he blesses the couple with the icons, which the couple then takes to their home.
To say that laymen cannot bless in this way, or to say "God bless you" is simply and utterly wrong.