Using this card is a mind game more than anything else. It's good to use this right after your first turn as your opponent won't know the theme of your deck. Your opponent's most frequent guesses will be DARK, LIGHT and EARTH, so using this card with a WATER, FIRE, or better yet, WIND monster, will slightly increase your chances of success.
If you plan to use this card and you're opponent has already discovered the theme of your deck, use this card with a monster that is different in attribute than the rest of your deck.
Flip Elemental Mistress Doriado face-down with a card effect and then use that monster as your target for this card. This could guarantee that your opponent draws two cards, in case you want to activate an effect that requires a minimum amount of cards in your opponent's hand. (i.e. Heavy Slump).
This card is good for a Mill Deck, because either way it fits your strategy.