Ok, general tips for "true" control decks:
-Needs disruption to survive the early game (coutners, discard, etc) against key spells;
-Needs some board sweepers to survive against aggro:
-Usually goes for card advantage, be it via draw spells, 2-for-1 cards (or X-for-1 to be precise) and recursion;
-Are usually mana-intensive, thus needing a lot of lands since it can't afford to miss a land drop during the first 4-5 turns (and most of them also played Storage Lands, in Standard, in order to accumulate mana faster);
- Needs a finisher that is either ABSURDLY hard to deal with, closes the match REALLY fast and/or has some sort of recursion itself.
Since blue is the "control color", per say, with black following closely behind, I'll post the finishers I played in my UB Teachings deck:
-Teferi (isn't a "finisher" of sorts, but sertainly can pack a punch, not to mention it makes it ABSURDLY hard for the opponent to fight back;
-Guile (punches hard, is nigh-unstoppable, has a CRAZY built-in ability AND "dodges" removal);
-Aeon Chronicler (it's card advantage AND a LARGE beater to boot);
-Tombstalker (beats hard, has evasion and can
come down for dirty cheap);
-Urza's Factory (great in attrition wars that go to long, AMAZINGLY good in the Control VS. Control match-up).