createDiscussionForm.html

<template name="createDiscussionForm">
  {{> quickForm collection="Discussions" id="createDiscussionForm" type="insert"}}
</template>

discussions.js

Discussions = new Meteor.Collection("discussions", {
  schema: new SimpleSchema({
    title: {
      type: String,
      min: 1,
      max: 25
    }
  })
});

// added afterwards to make this work
Discussions.allow({
  insert: function (userId, doc) {
    return true;
  }
});