How to identify lone pairs and bond pairs?

In a chemical bonding the  electrons that are in the outer most orbital are the one's involved in bonding. The aim of bonding is that each of the atoms must have an octet of electons ( but there are exception which do not follow this rule ) in their valence orbital in order to become stable.Atoms can either loses, gain or share electrons in order to reach this desired state. In a case where they share, they might share all their valence electrons either with the same or different atoms or a certain number of their electron which will end up with them having eight electrons in their valence orbital. Once the atoms have bonded, the remaining electrons that are not shared between the atoms are called the unshared elctron pair and the electrons that are shared and involved in forming bonds are called the shared electron pair. the unshared electron pair can be shared with another atom that has lost it's electrons, this pair is then called a lone pair.