Fortunately we have a few tricks to always guess correctly, such as Telepathy and Glasses of Urza to peek at opponents' hands and bounce like Gust of Wind to return cards to hand in order to guess them
Without Lands, nobody casts spells, nobody curves out, and the entire game becomes two players muttering about variance for much longer than they should
When selling energy cards, set a fair energy Pokmon card price that reflects the card's condition and rarity
Whether they have flying printed on them, gained flying before your Archetype of Imagination entered the battlefield, try to gain it after your Archetype of Imagination entered the battlefield, or are being granted flying continuously (say, by another Archetype of Imagination), they can't have flying for any reason while you control Archetype of Imagination
Use tools like a magnifying glass or a card holder to inspect corners, centering, and surface
The beauty of rental programs is that you can switch cards whenever you want, so you can borrow some cards, play with them for a while, and, once you get tired of the deck you're playing, swap them back in for something else, as long as you don't go over your rental limit