1) Understand the opening game - every character has unique ways in starting a match (Superman's f23, Fate's f2, Cyborg with grapple, GL b13). You should know all the common methods and how to counter them with your character. For example, Cyborg can punish superman's f23 opening with walkback d1 into PF. Cyborg can punish Fate's f2 opening with a neutral jump 2, and so on.
2) Understand the best normals and jump attacks of the opposing character, and how to whiff punish/trip guard them or bait them out. For example enchantress's f23 is a common string in neutral.
3)Understand common trade and projectile situations. For example in the Darkseid matchup if he blocks and IAFB, Cyborg can immediately punish a reversal omega beam with dash in MB roll into d1 PF. Another example with Cyborg is that against most zoners, if they block NB from full screen they will get hit by the next NB if they throw out a projectile (I call it the rule of two).
4)Understand the range you need to be in to be successful in a matchup. Cyborg's best range is at 3/4ths screen considering that's the farthest all his projectiles can reach (diagonal air fireball cannot reach further than 4 Cyborg backlashes away). However, in certain matchups certain zoning options are cut off, and another neutral gameplan is needed (example Hellboy/Starfire/Supergirl).
5)Have neutral setups with your character. Neutral setups are scenarios that can be used to bait a reaction from an opponent that leads into potential damage. For example, with Cyborg if the opponent attempts to hop over ground roomba at ranges 3-6, a diagonal NB will anti-air them right into it, and Cyborg can follow up with f3. Fate can place an orb on screen and if the opponent attempts to jump over at ranges 6-4, can anti-air with MB Amon Ra Blast. Even block strings that space your character just outside their attack range can bait counterpokes as well.