Identify yourself clearly first of all and introduce anyone else who is present. Try to indicate where they are placed in the room.
When offering a handshake, say something to indicate that you wish to shake hands, e.g., May I shake your hand?
When help is needed on unfamiliar ground, offer to help before doing so by saying, do you want to take my arm?. This will enable you to guide rather than propel the person.
When offering a seat, first place the person's hand on the back or the arm of the chair so that they are aware of the position of it.
When talking to a group, remember to say the name of the person to whom you are speaking. When talking in a group, ask everyone to say who they are before they speak.
At the end of a conversation do not leave someone talking to an empty space. Say when you wish to end a conversation or to move away.
A visually impaired person may use a guide dog. A guide dog is a working animal and should not be treated as a pet.