After researching and reviewing in preparation for this article, I can say that Mirrodin Besieged is a very good set in terms of Type 4 applicability, and is full of cards that are likely to make your stack better
In Meren, for instance, your smaller bodies like Sakura-Tribe Elder and Wood Elves will be pulling lands from your deck, and in conjunction with Cabal Coffers/Urborg, Tomb of Yawgmoth package you can realistically have a lot of mana available in the mid to late game
It even inspired one of the wildest tournament moments ever, when a player ripped their Chaos Orb into pieces and scattered it over their opponents board, trying to maximize its effect
You wont always be able to win with it, but try and take note of whether thats because of your deck choice, or because of the type of game people are angling for
If a card in a graveyard has in its mana cost, X is 0 when determining its mana value
In general, aim for images that are at least 1000 pixels on the short side, though larger is always better