tested in laravel 4.2 for belongsToMany relationships
if you’re in the model:
//copy attributes
$new = $this->replicate();
//save model before you recreate relations (so it has an id)
$new->push();
//reset relations on EXISTING MODEL (this way you can control which ones will be loaded
$this->relations = [];
//load relations on EXISTING MODEL
$this->load('relation1','relation2');
//re-sync everything
foreach ($this->relations as $relationName => $values){
$new->{$relationName}()->sync($values);
}