Wrong. You must micro else you'll never get out of platinum. Learn to macro and micro at the same time and that will get you a lot better results.
You never want to be at the point where you can macro like a grandmaster but have no idea how to engage your units and micro your army.
Why are you saying that when you're still in Platinum?
Mox, everyone is telling you to Inject better and build overlords, but how exactly do you inject better? Did anyone tell you? Do you simply go back to your bases and inject randomly?
No, you can use something called a "macro cycle" to help you remember to Inject better, build overlords to prevent supply cap and USE your larvae to keep your resources low.
This is the order of the cycle and since you're doing things in a logical order (cycle) it'll help you remember to keep up with the things that others have mentioned to help you keep your resources low.
1. Inject (Try to sync all your bases injects together, using the "Inject Method" Rockstar mentioned below)
2. Produce (Use your larvae)
3. Overlords (Don't get supply capped so you can constantly use your larvae and therefore minerals)
4. Spread Creep (Usually get a seperate queen dedicated to spreading creep)
You can practise just the first three together and add in the fourth step after you've gotten the hang of the timing of injects and producing or just step at a time, i.e get good at injecting, then injecting and producing after and so on.
A good tip is as well as using the 4, 5 and 6 to inject you can quickly tap 4 twice to center on your Main base and CHECK the time on your Inject Larvae (should be a grey bar above the hatch), as long as you sync all your injects you can just check one base and you'll know abouts when to quickly check back (press 4 twice) and inject and start the cycle again, eventually you'll do it so much that you won't have to check as much and instead go back right as your injects pop or just before.
So injecting is fairly quick, right? Producing, using your larvae (most of the time it's just 's' and holding down 'd' in the early game and later it'll be 'z' because zergling is a good unit :P) and making overlords sort of actually count as using your larvae, the step should actually be CHECK your supply and know when to build Overlords as part of your Production.
This shouldn't take you a long time, this leaves you with around... 20-30 seconds to do other necessary things such as scouting, upgrading, teching, building static defenses, microing fights, prongs and taking base. After all that's done... MACRO CYCLE AGAIN.
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