Then do it again.) Cascade, cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less
Shifting Sky can allow you to make all nonland permanents Blue, allowing Llawan to bounce everything, while cards like Swirl the Mists let you change Llawans effects so that they can affect cards of other colors instead
Some other graveyard-casting reduction cards are Doc Aurlock, Grizzled Genius and Savvy Trader
You can spend crystals on booster packs, bundles and customisation items for your avatar and deck
Vesperlark Reveillark's little buddy also happens to have tons of Commander potential
It is one thing to prioritize another card over it, but entirely another to pass a turn without playing something because you want to get an extra +1/+1 counter via your Juniper Order Rootweaver