This endgame is not easy at all and indeed Black has to be very careful. As White life is a bit easier since we have a better chance to activate our king, but there's still a game of chess to be played here. Even with few pieces on the board chess is an extremely complicated game. For example, I once maanged to win the following position (as Black, Black to move) to a 1700-rated opponent in a 90+30 game:
8/p4p2/3kp1p1/1p5p/3P4/PP2KPPP/8/8 b - - 0 40
Step 1 of our plan should be moving our king to the 4th rank and keeping it stable there. 1.Kf3 Kd7 2.Ke4 Kd6 could be a reasonable continuation.
Depending on how Black sets up, we'll probably need some pawn moves like a4 or f4 to stop the enemy pawns from kicking our king our of the 4th row. For example Black pawns on b5, e5 and f5 at the same time could be bad news In most cases we also want to avoid making unnecessary pawn moves so we can 1: avoid turning them into weaknesses and 2: have some tempi to waste in case we reach a potential zugzwang situation. Think of something like the "e" pawns getting traded, Black pawns on f5 and b5, White pawns on b4 and f4, Kings on d6 and d4, and the a, g and h pawns still alive in some square.
But it's hard to define a general "technique" or "method" to guarantee a draw. Instead, each of Black moves will generate several lines where we must calculate precisely. For example Black can try to attack our queenside with something like 1.Kf3 Kd7 2.Ke4 Kc6. Now White has to choose between a3, Ke5 or Kd4 and I don't think we can come up with a rule to help us decide other than calculate each line as deep our ability lets us (specially since in practical play we won't probably just be trying to hold a draw but also punish Black's most ambitious attempts)