Smurfette usually kisses a Smurf when they give her a gift.
Smurfette Day was a day designated by Papa Smurf on the anniversary of Smurfette becoming a real Smurf in the episode "Smurf-Colored Glasses". As far as is known, this may be the only time that such a day was celebrated, usually with the Smurfs presenting Smurfette with various gifts.