You can select them in any ways you wantmaybe you just like those colorsbut three things to keep an eye out for are: Any strong rares in those colors that you're excited to play A lot of removal cards (Cards which destroy or otherwise deal with your opponent's creatures.) Evasion (A lot of Sealed Deck games are won with flying creatures or hard-to-block cards.) Additionally, another huge element to look out for are good synergies and multicolor cards
Youre limited to finding artifacts, but it easily sets up an artifact recursion effect like Trash for Treasure and Daretti, Scrap Savant
Also, Im heavily biased towards new cards (sorry, reprints) and Standard playability, but Im also including an interesting Commander card here and there, not to mention the legendary powerhouses people are already trying to build around
Meanwhile, Helpful Hunter doesn't look like much, but if you look at the greatest tribal decks of all time, they pretty much all have a two-drop that cantrips when it enters the battlefield, like Silvergill Adept in Merfolk or Elvish Visionary in Elves
