Although watching your opponent IS more important, make sure you are constantly aware of your percent damage (and your opponent's), as well as your location on stage relative to platforms, the ledge, or any obstacles, as all of these things should directly influence your decision making for DI, combos, and neutral game. As stated before, if you have issues with tech, it can help to give your character more attention. In fact, you can often put the majority of your focus on your own character with little consequence. The only exception is neutral game. If you are performing a technically demanding chaingrab, for example, it can be beneficial to focus heavily on your character to more accurately see EXACTLY when the throw animation ends, in order to react immediately more easily. You can use your peripheral vision to monitor their DI and react accordingly. You can do similar things while techchasing and combo'ing too. What if you want to execute a combo that involves a edge cancel? It's hard not to give your character a little extra focus to get the spacing right. You'll find yourself going back and forth quite a bit most likely, which is good. But during neutral, you need to be able to react as quickly as possible to your opponent's every move, so you want to find the best way to stay focused on your opponent without sacrificing control of your own character. It's easier said than done, and it's a challenge that all player's deal with. Confidence in your tech certainly helps.