Hindu Wedding Traditions:
Background: Hindu Weddings Explained
See references to exchange of garlands
See also references to the coconut:
Groom's arrival: as a gift between the families
Viddai - The parting Ceremony - a modern development I suspect!
See Google images for many photographs of garlands and the coconut used in ceremonies
Why garland ceremony in Hindu marriage?
Coconuts in Hindu ritual
'Gath Bandhan' (Tying of the Nuptial Knot) Scarves placed around the bride and groom are tied together symbolizing their eternal bond. This signifies their pledge before God to love each other and remain faithful. - A variation on the Western Hand-fasting ceremony.