Wedding Season

Isn't their venue stunning?  Classic Victorian.

Don't you just love receiving wedding invitations in the post?  I get so excited for the occasion and for being able to head out to the shops and buy a beautiful, loving gift for the couple and today was one of those days!  I opened up my letter box and gorgeous sparkling envelope was awaiting me!  A dear friend from high school is getting married later this year and instead of having a gift registry they are having a wishing well at the reception for gifts to be given.  I've never had to gift a wishing well before and not quite sure what the etiquette is for such occasions.  Can anyone help?