The flexibility is the beauty of the mechanic, allowing you to have two different effects on the same card depending on how much mana you have
Card thickness generally ranges from 0.01 to 0.03 inches (0.25 to 0.76mm) , a factor that affects the feel during shuffling and gameplay
But two rectangles for 1 mana remains a good deal, especially with synergies
For example, Sokka's first card is good at supporting his friends, his second card shows his personal growth as he learns lessons and embraces his technical aptitude, and his final card is him coming into his own as a leader
Pokemon Card Maker by Rarity Pick the rarity style that matches the kind of card you want to mock up
With enough luck, you could even repeat this process a few times and gain tons of value