Straight forward--Mill your opponent until you win.
For the Mill strategy, Ruin Crab has Landfall Milling. Just 2 on the field will Mill 6 cards per land played. Minister of Inquiries and Persistent Petitioners add additional Mill sources for cheap casting costs and can help block if necessary. Finally, Glimpse the Unthinkable is a nasty 10 card Mill for 2 mana.
All this is so you can win either because your opponent cannot draw a card or because you have stomped them with 1 mana cost 5/5 Jace's Phantasms and/or ridiculously over-powered Consuming Aberrations.
To help get the necessary components together and ensure a steady flow of Landfall Triggers, there is a complete playset of Thought Scour which will Mill your opponent for 2 and let you draw a card. In a Legacy format, Accumulated Knowledge is better. Additionally, full playsets of Counterspell and Mana Leak will keep your opponents at bay while you set up your Mill outlets.
Not the most budget-friendly in my opinion at about $50, but not a bad price for a fairly consistent deck that will Mill out your opponents' 60 card deck in roughly 9 turns (range of 8-10 that I usually see) never mind having multiple 5/5 Jace's Phantasms likely and at least 1 Consuming Aberration that can 1-shot your opponent before you have finished Milling their deck.
Realistically, I have overwhelmed my opponent with big creatures before I milled them out--turn 2 you can cast Glimpse the Unthinkable and meet the requirement for all of your 1 CMC Jace's Phantasms to enter as 5/5 creatures, so turn 3 you can have multiple of these and by turn 5 you'll be adding Consuming Abberations with wickedly large Power/Toughness.
