Combine this card with Oracle Guardian, Gemini to ensure your opponent will have to use 2 cards to guard, even if they have a 11000 Power Vanguard (unless the opponent has a Lark Pigeon in the soul which could be called as a guardian if the opponent has a Pale Moon vanguard and no cards in hand at the beggining of the guard step)
It may be better to reserve this card's attack for last, in order to add the effects of any triggers on it.
You should avoid placing Tom on the field earlier than necessary. This card is much more valuable during the late game, when the pressure for defense rises, and if it appears early your opponent might take measures to destroy it before it can fulfill that potential.
Alternatively, you can use this to your advantage if you have more Silent Tom in hand, in order to make your opponent waste effort and resources while you are able to conserve shield.