The important thing is that it is linked in your mind with Samhain, that way every time you look at the tatoo that linkage to Samhain will be present in your thoughts. You really don't need to do more than that.
Or in addition, while you are getting the tatoo think about how you are doing it as a way of connecting to Samhain. Think about what Samhain (and therefore the tatoo) mean to you. That will help set that connection.