For example, if youre on the play and your starting hand after a mulligan contains a one-drop, two two-drops, two four-drops and two five-drops, then I will usually start on turn one by inking the worst four-drop
Chandras +2 loyalty ability is a good way to dig a little deeper into your deck, with the cost of discarding an actual benefit in some decks that care about getting cards into the graveyard, and the cost of sacrificing an artifact often negligible when you can easily have extra artifact tokens lying around: Treasures, Food, Blood, etc
And the Avatar: The Last Airbender set is a great lesson in how deep and complex that process can be
Not only are decks often chock-full of hits, but given the lack of good two-mana plays and necessity to have a creature on the battlefield early, Im happy to include Augur of Bolas in my decks
Untap it
This may be a slow progression for the game to take so many turns to increase your mana and it may be easily disruptable, but its well worth doing in some situations