Choosing an idea for your special invitation should be based on your own passion. If you like new nuance, maybe this can be your reference for making different birthday invitation template.
The design of the birthday invitation template should be adjusted and matched with your birthday event concept.
The design of the invitation template should pretty much determine the atmosphere and nuance of the invitation.
One way for making the birthday invitation template is using best colour. You can use different colour than basic colour in your invitation. Using different colour for the birthday should adding different sense.