When you cast Goblin Tutor, search your library for a card with goblin in its name, reveal it, and put it into your hand
Including 2-3 cards from a third color for a specific effect can work if your pool supports it
Even in a 40 life format (*cough* Commander *cough*), Athreos tends to be a great long-game clock that also nets you good stuff here and there, at least in the early game
We made a cycle of twobrid spells
Once a creature is renowned, the next time they would deal combat damage to a player you get to double the number of +1/+1 counters on it, helping them deal more and more damage every time they attack
This deck clearly manages to do the best of the three colors with great resilience, generate a lot of mana and convert it into big damage, which will be intensified through other cards, and it's pretty easy to make a nice list