The longer the game goes on - more careful you need to be with your plays!!! . Pyke players often get a false sense of security because of his strong early game, so keep that in mind.
DO NOT AUTOMAX skills at level 1. You can quickly adapt to the situation maxing either Q or E, for example E can come in handy as a second flash if you end up in a tricky situation, or enemies stand behind minions as they arrive, a sudden E from bushes can catch them off guard.
You do not chat as Pyke (except if you wanna quickly BM which can be good, but after that make sure to /mute all instantly). You have no time to spare. You should not have any sympathy towards your enemies as you cannot afford it, unlike those "wholesome" Bard or cowbell Alistar players who will then proceed to outscale you into oblivion.
Know your limits. No other champion gets this much value from just knowing how deep exactly it can venture - your passive practically makes you a catlike creature with 9 lives if you develop enough gamesense to see if you're overextending, or you're positioning yourself just right to make enemies waste their abilities on you, while being somewhat safe and ready to E-W out if needed.
Pyke's design screams "be like water". You need to learn to adapt, because he literally has no unplayable matchups and can be useful in any situation if played well. If you're permalosing against certain champions, it just means that you're lacking game sense or you need to play a little bit more carefully, abusing their cooldowns or mistakes.
Pyke's incredibly strong if you're able to optimize your playstyle according to his core strenghts. W sounds from the enemy POV do actually scare people and make them lose their grit. Start holding your Q against dashy champions like Ezreal or Lucian instead of just throwing it out instantly. Always think about what lane you wanna path to next while recalling. It is yours job alone to do everything that is possible to win the game early, by setting up deep vision and quickly following up on skirmishes before the enemy support can.
You apply pressure by hanging around while waiting for the perfect opportunity to strike. Just because someone is in your range, does not mean you need to all-in. Most of the time when the enemies are acting all confident around you, they believe they've got an ace up their sleeve and they can desintegrate you the second you try to do something about them. I personally have developped an ability to see if the enemy currently has flash or not just by the way they move, and i'm pretty sure you'll be able too.
Always warm up before your ranked games. If you spend half of the game waking up and trying to get a hold on your own abilities instead of keeping a proactive and confident edgelordy-like appearance, you're very likely to have the game decide for you on either you're gonna win or lose. This also means that you are vulnerable to the overconfidence effect - insta-queueing again after winning a game while not being as capable of playing at your peak anymore. I recommend taking a short break after every game to calm down and see if you can actually continue stomping. One cannot simply AUTOPILOT through a game as Pyke so do not play in the evening when you're too tired to think, trust me you're not gonna enjoy it. You ALWAYS invade or cheese at the start of the game, and it's more important than giving a leash to your jungler. A proper cheese always allows to at least gain decent lane pressure, if not win the game from it's first minutes as it often happens in lower elos, where people have a sip of cola or just act silly/eepy before minions spawn (it's a free real estate). Also, it is your job to quickly force good fights for your team when you have a number/positioning advantage.
You will need to master the ult cross placement, to be able to live in certain situations by hitting enemies with the edges instead of center, and sometimes use it as a teleport behind an enemy when required and not just an execute.
Overall, just try stuff. It's no better to be safe than sorry :)