Here is a list of proposals for acceptable smiles that could be userfied. Feel free to add an idea to the list, and discuss on the talk page.
Proposal 1
{{{1|<includeonly>~~</includeonly>~}}} has smiled at you! Smiles promote WikiLove and hopefully this one has made your day better. Happy editing! <!-- Smile to others by using {{SUBST:notyetdecided}}. -->
Proposal 2
Basically just a template to add a smile with only your own text, details on how to smile commented out.
{{{1|}}} <!-- Smile to others by using {{SUBST:notyetdecided|a message}}. -->