Based on my experience. Of course, there’s plenty of rules mistakes and deck building mistakes, but I’m focusing on easy-to-fix problems. Also, even though I’m giving specific examples, I’m trying to fix larger problems.
Sure, you’ll lose if you lose all of your life, and against decks such as burn, you really need to protect your lifetotal. Most of the time, however, your life isn’t that important. It does decide who wins, so you’ll have to do something about it eventually, but quite often the game (especially right now) is more about maneuvering yourself into a position where you have enough control of the board or evasion to put yourself ahead enough to win eventually.
The key is to know which kind of game your playing right then. The basic rule: If your opponent is throwing his resources at you from the beginning, in order to kill as fast as possible, protect your life. Otherwise its not that important.
Being Overly Protective of Their Cards
Something I noticed playing in GP Strasbourg (and yes, there are beginners at GPs as well): A couple of players would do everything they could in order to protect their [scryfall]Hooded Hydra[/scryfall]. Apparently they had internalized that [scryfall]Hooded Hydra[/scryfall] is a very strong card, but they hadn’t really figured out why.
Hooded Hydra is a strong card specifically because you don’t need to protect it. If it dies, you get a comparable edge on the board with all the snakes. Of course, it depends on the situation whether you want the snakes or not (they can be very bad if you know your opponent is playing something that can kill small creatures easily, but they can be extremely good, if your playing things like [scryfall]Trumpet Blast[/scryfall]).
I also see people not attacking, or not blocking because they are afraid of some trick. Sometimes this is right, but not that often. You need to figure these things out objectively, not based on a bad experience, or fear of losing something.
Overestimating the Impact of Luck
Some time ago I was at an FNM draft. One of the players was a first timer. He had never drafted before and since this wasn’t a timed draft, he would use a lot of time to make his decisions (actually, way too much time even for a first timer, but lets not delve too deeply into that or all of his other inapproriate behavior). I probably rolled my eyes way too much when I was paired against him, because I saw his earlier round had gone to time and ended in a draw because he wouldn’t stop messaging on his phone, and apparently he didn’t learn anything from it either.
And, sure enough, after I beat him, he couldn’t help himself and complain about his bad luck. It didn’t occur to him that maybe if he had been paying more attention to the game, he might have won. Or perhaps my years of experience in the game might have given me an edge in drafting, deck building, sideboarding and of course the games themselves.
Sure, luck is a factor. A big factor in fact, but it isn’t that simple. There was a time when Kai Budde won everything. Was he just that lucky, or did he just prepare that well? Probably some of both, but even luck is something you just need to able to utilise. You still need to know what to do with the cards you are draw. You still need to be able to identify the cards you need to put in your deck to be able to draw them.
Not Shuffling Enough
Speaking of luck…
Many people say seven rifle shuffles is enough, because that’s how much you need to shuffle in order to not know where the cards are. I’m not sure if this is true, because I believe a skilled individual could still have a strong chance of being able to “follow” one card in the deck, which might give a pretty big advantage. However, what seven rifles definitely doesn’t do, is randomize the deck enough to be really random. Of course, you can’t really achieve that manually anyhow, but you can try to do more.
You do have to keep a fast enough pace, so you can’t really use too much time on shuffling, but you should do it as thoroughly as possible, and hope your opponent contributes a bit as well.