AWS CloudFormation conditional tagging

I have a similar need and don't want unused tags lying around either. I've gotten it working using the following snippet:

"Tags": [
  ...,
  {
    "Fn::If": [
      "MyCondition",
      {"Key": "MyKey", "Value": "MyValue"},
      {"Ref": "AWS::NoValue"}
    ]
  }
],

And if you're using YAML

  Tags:
    - 'Fn::If':
      - MyCondition
      -
        Key: MyKey
        Value: MyValue
      - !Ref AWS::NoValue