This is just a simple discard deck created for standard tournaments which, so far, has earned consistent success. It's essentially equally divided into creature removal, creature/non-combat damage, and discard. The two main areas that still need improving is 'Go For the Throat' and artifact/enchantment conflict. Currently I do not own any 'Go For the Throat', so I didn't add them, but they will likely replace four cards in the sideboard, probably Suffer the Past and Horrifying Revelation. Until then, I swap in Quag Sickness for black removal, and I also find it useful to contest indestructibles. Black unfortunately lacks enchantment/artifact removal, so I'd be interested in any ideas that could be useful against 'Quest for the Holy Relic', 'Luminarch Ascension', etc. The only card I know currently that could prove useful is 'Vampire Hexmage', which may only be useful against some counter cards, but not all artifacts/enchantments.
The concept of this deck is rather simple: whither their hand and remove their creatures during the early game until they can only play the card they draw each turn. Of the low-cost discard spells to activate on turn 1, 'Inquisition of Kozilek' and 'Duress' prove the most useful. 'Inquisition of Kozilek' allows you to view their entire hand, prepare for what they will play, and also attempt to prevent them from playing early game threats by removing cards with less than 3 mana. 'Duress' has a similar technique, but can only be used on non-creatures/non-lands, and therefore is useful after 'Inquisition of Kozilek' to remove larger spells. Follow this up with removal spells, such as 'Doom Blade' and 'Grasp of Darkness'. Creatures are not priority unless 'Gatekeeper of Malikir' is used for creature removal.
After the first few turns, your opponent's hand will typically be exhausted from discarding, playing land, and playing creatures. More than likely they've managed to save their best cards whenever you forced them to discard, so activating 'Liliana's Specter', 'Bloodhusk Ritualist', or 'Mind Rot' should further limit their abilities. From this point on, you will have enough mana to play creatures that either double as offense/defense and creature removal or discard while maintaining control of the battlefield and your opponent's hand. 'Sign in Blood' can be used to replenish your own hand, and your larger creatures can be used or saved to maintain the game. 'Liliana Vess' is useful for its multiple potentials and Mimic Vat combines well with most of your creatures, not to mention you can use it with your opponent's creatures. Of the creatures that have on-cast abilities, combining 'Liliana's Specter' with Mimic Vat will allow you to bring in a token of the card at any time for only three mana. If your opponent has no cards, Mimic Vat can be used after they draw, forcing them to discard that card unless it's an instant spell they can activate.
As a final note, I've tested 'Sangromancer' and 'Massacre Wurm' and I have found them both to be generally useful cards for a standard discard deck. 'Sangromancer' not only provides a flying 3/3, but allows you to gain life whenever a card enters your opponent's graveyard. 'Massacre Wurm' was originally added as a counter for spawn decks, as it typically will decimate an opponent's field of 'Eldrazi Tokens', but I've also found it to be useful in other circumstances. It provides offense and defense, and combined with Mimic Vat you only need to pay three mana to return it to the field, activate its effect, and attack/block your opponent.