Plenty of what I’ve done over this past week has been mainly exploratory, with a reading on fighting game fundamentals by Guilty Gear Champion, Machabo: http://guiltygearsweden.com/strategy/machaboo-on-fundamentals-for-those-that-want-to-become-good-at-gg/
Without going into the same depth that the article goes into, the main idea is that you prepare yourself with specific tools to prevent enemy offense, mainly anti-air attacks. In 2D fighting games, aerial attacks tend to lead into longer strings of attacks. As the most conventional form of offense, it is important to know how to prevent such a tactic from consistently working.
Articles on game balance and mind games (Yomi):
It’s a pretty commonly cited article in the realm of competitive fighting communities but still very important. These go a bit into game balance and reading the minds of opponents. As you progress in skill and experience you should be able to predict what your opponent will predict and respond accordingly, with the idea being that you are able to think in multiple layers if your opponent does.