Pushing a Single Run's Score Higher — The Mechanics of High Scores
If you're chasing a high score, you first need to know where the score comes from.
In this game, points come from four places.

The first is depth.
Every 1m you descend is 1 point.
It's the baseline score that stacks the farther you go, so simply surviving longer is itself points.
The second is carrots.
Each one is 10 points, and the combo multiplier gets applied on top of that.
The third is near-misses — graze past a rock by a hair and 50 points get tacked on.
The fourth is the pocket watch, at 30 points.
Of these, the one with the biggest swing is, by far, carrot points multiplied by the combo.
Depth points pile up faithfully but have no explosive power, while combos, once they hit ×5, turn a single carrot into 50 points.
So the main thread of high scoring is "surviving long while keeping a combo going for a long time." In fact, those two point the same direction.
Near-misses are a reward for taking on risk.
They're worth going for on purpose, but hugging a rock when you're not invincible is a gamble.
Only get greedy as long as it won't break your combo.
In the end, the answer on the scoreboard is simple: don't break the chain, and go far.