There's no restrictions on stats, type, or mana value of the creature being brought back to the battlefield, and the only thing you have to give up to play it is the three generic, one white to play it
Still, even Knight of Malice is good if you have a white permanent on Turn 3, namely History of Benalia
You can follow any principles for sorting your Magic cards
A Clue is a colorless artifact token with the ability ", Sacrifice this artifact: Draw a card." So, as you can see, whenever a spell or ability tells you to Investigate, what you're really doing is making a Clue that can be turned into a card later
Cards that cantrip (draw a card for one mana) are also a vital part of the strategy