There's a lot of signs early on, but one piece of dialogue encapsulates the epitome of who Walt is/will become as the villian said at the end of 2x04 in the Walt-Jesse RV fight:
"There is no your half of the money. There is only my all of it. Do you understand? Why should I be penalized because of your sloppiness? ...because I'm the producer, right?"
Walt is the mastermind in this operation and already set to take all the credit, but in the same breath is readily inclined to put all the blame on Jesse.
And when you look at his actions prior to that, he's the one who wanted to continue business with Tuco, putting them in the situation to be kidnapped and held at gunpoint later; he suggested they meet at an abandoned car lot, which is where No-Doze got killed before their eyes and set off a chain reaction for Gonzo to go back there, die, and alert DEA to their business practices (I'm actually impressed Jesse called out his greed so early on like just 1 episode later). He is the one calling all the shots, and yet Jesse takes all the fault.
He thinks he is the one getting screwed in their business; he thinks Skyler being mad at him is a consequential result of him being involved with their cooking, NOT that he's secretly doing this thing that she still doesn't know about here, and he places the responsibility to Jesse calling his house, as he says he needs to smooth things over, so he can (and with the full intent that he) get back to cooking.
Jesse is the suspect when his car, the one used in the middle of the night to spring threats upon them at gunpoint, is found at the scene...the one facing all the potential legal consequences; meanwhile Walt gets to play like the poor old lost father and husband with cancer in a fugue state away from all the crime.
In that same 2x04 fight in the RV, Walt calls him "too stupid" and it's a good addition when thinking about comparing where they each constantly end up, as well; because Walt had his own house, his own family, and a normal job and he ruined it to sell *cough, cough, Walter White's the real idiot* (and logically he SHOULD be the one that consequences, more than just his wife giving him the cold shoulder, catch up to more quickly); I only say this to lead to 1 specific commentation on Jesse's solo characterization. Because Jesse didn't have the same life that Walt had; he essentially had nothing to lose by comparison when he first got into selling. Jesse is passive in his duos ( ¹in his partnerships, ²in romantic relationships.. ) When it comes to his and Walt's partnership, he was never the mastermind...or the leader in his own chosen doings (he wasn't even the real leader with his prior parther, whose cousin was their distributor). And Jesse's not innocent at all in this, but he finds himself in the trouble he does after the fact, because he's at the hand of other people's direction (and he's also too trusting). He gets involved with the wrong people and he 'stupidly' makes mistakes and he doesn't really know what he's doing with the cooking, or how to make a drug deal when he's been doing this for longer than Walt. He is nonchalant at the start, and naive in his way of doing things and that gets him into hot water.
Here is 1 glorious shot from that RV fight. Their physical fights are really spectacular television moments:
