However, if you want a guideline for what kind of cards to look out for, it's good to refer to the Limited archetypes available
12 Jetfire, Ingenious Scientist // Jetfire, Air Guardian Jetfire, Ingenious Scientist is a 3/4 flying creature that when conditions are met, can help ramp up mana
But maybe a couple copies could make for a decent way to refuel in longer games
Not a biggie if you are winning but it isn't a boost to the value of the card
Threshold CARDNAME has "2B, ocT, Sacrifice CARDNAME: Remove target card in any graveyard from the game." as long as you have ten or more cards in your graveyard." UL04_XR Land R ocT: Add R to your mana pool and CARDNAME deals 1 damage to you
WB Humans, attrition (add green for more of both) UR Noncreature spells, but sometimes just instants & sorceries (add white to get extra value out of your Cycling noncreature spells) BG Mutate, Graveyard (add U for more Mutate support) RW Cycling, go wide (add B for more human tokens to go wide with) GU Mutate, goodstuff (add R for more good stuff?) To be honest, I havent felt this unsure about a formats archetypes in a while