It Depends
Time for a car analogy. What's the right way to make your car faster? More reliable? More efficient? Have higher resale value?
There's really only one answer to all those questions. And that answer is "It depends." It depends on what your priorities are. It depends on where you're starting. It depends on what you mean by those questions. It depends on how much you can spend to meet your priorities. Does faster mean top speed, trap time in the ¼ mile, or 0-60 time? Is reliability about MTBF, cost to repair, or total downtime? Is efficiency about moving one person from home to office, 50 people from a suburb to an urban core, or moving 400T of stuff from one end of a strip mine to another?
The same is true in software development. Want your software to be faster? Want it to crash less? Use less resources? Reduce time to market? If someone comes in with a silver bullet and says they know the right answer to that question a-priori, they're almost certainly wrong, and if they happen to be correct, in your exact case, they got lucky.
Sure, we have best practices, and we should probably follow them, but when you get down to it, those best practices are guidelines. If you really have no clue about what you're trying to do and why then best practices are a good place to start, until you know better. And that's the thing.
When you know better you should choose to do the right thing. Because the right thing depends on knowing why you're doing something. Engineering is about tradeoffs, but the only way to make informed decisions is to know what you're trading between, and why. Because *it depends."
Once you know what you're minimizing and what you're maximizing and what the cost functions are between them, you can get something close to the right answer. For your specific situation. At that particular time. With those particular constraints.