We found that Santiago was the only place in Cuba that we were actually pestered by some pesty locals asking for stuff.....and this only on our second visit there i.e. they are learning.
Unique Suggestions: Do not give stuff to people on the streets if you have no relationship with them at all. You will only attract more people. Save it for the person who gave you directions, or suggested a good hotel.
Try not to be rude getting rid of them, but a stern "No Gracias" should work. If that doesn't work, ask another Cuban to ask them to leave you alone.