When it comes to games in general, I think I follow a pretty general guideline if I want to, as they say, "Git Gud."
First, I'd try to play against people that are better than me. They do interesting things that, after a few games into playing Netrunner, I'd assume are counter productive. But then, once you see the results of these plays, you might determine that in fact, these plays are ultimately how they won the game.
For instance, playing criminal against AGinfusion, you might play an Account Siphon so that it gets bounced, all so you can land the Legwork you wanted. "Wasting" cards is fine, after all, if it leads to a board state in which you are winning.
Second, when I get "rekt," then I try to figure out what I could have done differently. Sure, you could ask your opponent, and it's helpful, and if you're new and want to get better, asking is great, but I think you'll eventually reach a cap where what they say to help is only marginally helpful. Instead, if you try to figure out a solution yourself, you develop a habit of thinking about problems relevant to Netrunner that you might be able to use in a game, without the benefit of hindsight.
Third, I like to keep in mind that no matter how good a player I might like to think I am, I will lose, and sometimes, I will be absolutely destroyed. And there will be very little I can do about it. If you're thinking about entering bigger tournaments someday, knowing how to deal with tilt is important. (Keep in mind that I know nothing of your prior tournament experience with other games, so this is pretty general.)
Finally, no matter what, make gutsy plays. Calculation is all well and good, but sometimes you still have to bluff, and the fact that they can work is part of what keeps me playing.