Does it seem a bit old fashioned to say "pitch it up, hit the stumps"?
In these days of slower ball bouncers, enforcers and bowling dry outside off stump you might think so. Actually, it's still an effective way to bowl in most situations.
Swing bowler on a slow English pitch in May? Yes.
Spinner on a Bunsen burner? Absolutely.
Fast bowler on a flat deck? Without doubt.
It's harder to score with no width. It's also mostly played straight. With good fielders at mid on, mid off, extra cover and midwicket you have a powerful defence. Sometimes, that's all you need to take wickets.
When you want wickets through aggressive bowling, you keep bowled and LBW up for grabs even if your main form of dismissal is something else.
Even at the death - when bowling length has become a cardinal sin - you can bowl straight and still cause problems to batsmen swinging hard.
Of course, you have other options. Batsman have different styles and weaknesses. Sometimes match situations demand you change your line and length. You have to be adaptable. Yet, most of the time hitting the stumps is the simplest way to achieve your aim.
When I was growing up in club cricket, two phrases were often uttered,
"You miss, I hit"
"A straight ball is a happy ball"
These are clichés, but they are clichés precisely because they are true.
And it's so easy to measure.
You can simply make sure you are bowling on PitchVision in practice (or other notational system). Keep track of how often the ball would have hit the stumps.
You'll be surprised how many times you miss. In this case study, my club's bowlers managed just 15% on the line of the stumps; and we thought they were accurate!.
Over time, and with focus your numbers will improve far more quickly than running up and wanging it in the general direction of the other end.
So ask yourself, are you hitting the stumps enough?