LotV: first tips
In this article I'm going to get straight to the point and try to share my experience as a player who's been in the scene for a long time, to help you approach LotV as competitively as possible.
Going from Wings of Liberty to Heart of the Swarm was one thing. Going from HotS to LotV is another, and much harder in my opinion. Just the fact of starting with 12 workers instead of 6 is a massive shake-up. Now every player starts from the very first second with an almost saturated base. What does that mean? To me, players have less "time" to make a build choice. You have to make a decision instantly: am I putting down a spawning pool right away, or am I quickly droning to 17 to put down a hatchery first? Past the 40-second mark of the game, that choice has to be made and executed.
Taking that into account, I personally choose to always send 1 drone at the very start of the game to scout my opponent. Here's my reasoning: do you honestly think starting at 11 drones instead of 12 is a sacrifice that can influence the outcome (win/loss) of the game, compared to knowing immediately what your opponent went for? On top of that, it lets you adapt your game plan perfectly to what your opponent is preparing.
Gone are the poker-style gambles like "I'll hatch first in ZvZ hoping he doesn't pool 10 on the other side". This move to 12 workers now reduces the random factor influencing a game's outcome as much as possible (something that was hugely present in HotS).
But that was an easy tip to understand and execute. Now comes the trickier part: making the right choices among the countless possibilities the game offers, all while keeping in mind that you're playing against someone who's also going to try to adapt to you.
You'd almost need to write a whole book to go through every possible strategy and its respective counters. My goal isn't to help you counter liberators (ps: 3 corrosive biles to kill one :D), but rather to teach you to think about the possibilities the game offers you and to take the initiative yourself. Because that's how you improve.
An extremely important point: after a loss you should always reason as follows: what should I have done to win? That thought process can take as little as 5 seconds — "I should have walled after seeing that" — or take as long as watching the replay if it isn't obvious at first glance. Because if you keep playing, the same situation will keep happening. And at that point, you need to snap out of it and go with the plan you thought through after your previous loss.
If you apply this point, you will undeniably improve, because you'll be expanding your knowledge of the game and learning to react to an ever-wider range of strategies. This can be a player's main strength if their macro management isn't excellent.
Speaking of which, let's talk about macro. It's been made relatively simpler, especially for Zerg. Indeed, in LotV it's possible to re-inject on hatcheries (as I'm writing these lines) even if an injection is already in progress.
Quick practical tip: instead of hopping from hatch to hatch to inject like in HotS, go to a hatch with the "camera base" hotkey, select the queen there, and empty her energy into injections while holding shift. That way the queen will inject continuously as many times as you repeated the action. You can then use that time for other actions (other injections on another hatch) while the previous queen keeps re-injecting on top of her own injections.
Something I want to bring up that's related to macro is APM. It's often used as a reference point, especially by casters.
Above all, don't focus on it.
Sure, having a high average can only be beneficial (and even then, are they useful actions?). What you should really keep in mind is: as long as I manage to correctly execute everything I want to do at a given moment, without the opponent being able to gain an advantage from it, that's enough.
Personally, I've always had a fairly low average APM (around 150) simply because early in the game I only focus on actions that seem "useful" to me (from 0 to 2 minutes I run at an average of 80), but when I play an opponent who brings tempo into the game (drops, multi-pronging, etc.), my average is often around 300.
Last part for this article: stay in touch with other players, and talk with them. Discuss strategy counters (always taking other players' reactions with a grain of salt), and don't hesitate to reach out to "known" players to ask for advice with concise, targeted questions.