Most hand-plane problems aren't hand-plane problems. They're setup problems wearing a disguise.
The plane was last used on something else, for a different job, at a different depth. You pick it up, run it across your project, and the first shaving tears out or chatters or only comes off one side. So you blame the iron, or the wood, or your technique. Nine times out of ten, the problem started before you touched the workpiece.
Experienced hand-plane users spend two minutes at the bench before they do anything. That's the set. It's not ritual. It's the reset that makes every pass after it predictable.
Five things you're adjusting
On a Bailey-pattern bevel-down bench plane, five things move.
Depth of cut. The brass wheel at the back. Clockwise extends the iron, counterclockwise retracts. You want barely visible, a few thousandths past the sole on a smoother, more on a jack. Sight down from the toe. You're looking for a hair-thin dark line across the mouth opening. If you're squinting and not sure it's there, it's probably right.
Lateral alignment. The lever beside the cap iron tips the blade left or right. An uneven shaving, thick on one side or nonexistent on the other, means this needs a nudge.
Mouth opening. The gap in front of the iron. Tight mouth holds the fibers down and suppresses tearout on finish passes. Open mouth clears thick shavings during heavy removal. If your plane has an adjustable frog, move it forward for tight, back for open. Fixed-frog planes are designed around one job. Use them for that job.
Cap iron distance. How far the chip breaker sits from the cutting edge. Difficult grain with interlocking figure gets a close setting, 0.3 to 0.5mm. Straight-grained stock for removal work gets 1 to 2mm. Once it's set and the iron assembly is back in the plane, leave it alone until the wood changes.
Frog seating. You don't adjust this at the bench, but you need to know about it. The frog has to sit flat against the body casting. A rocking frog produces chatter that sounds exactly like a dull iron. If the plane chatters on wood that should cut cleanly and the iron is sharp, check the frog before you sharpen again.
The two-minute sequence
Do this at the start of every session.
First, check the iron. Thumbnail test: light contact, no pressure. If the edge catches, it's sharp. If it slides, sharpen first. Everything else is irrelevant on a dull iron.
Second, sight down the sole and set depth to barely visible. When in doubt, go shallower. You can always deepen. Recovering from a gouge is a different conversation.
Third, check lateral alignment. Eye down the sole. The iron edge should look parallel to the mouth opening across its full width.
Fourth, check the mouth. Finishing work or removal work? Set it accordingly.
Fifth, take a test shaving on scrap. Not your project piece. Find a scrap of the same species and similar grain, run one pass, and read the result. Continuous and thin means you're set. Broken means depth or grain direction. Uneven means lateral. If it tears, lighten the cut before moving the cap iron. If it chatters at a very shallow setting, try going slightly deeper. A too-light pass on a slightly tired edge chatters more than a proper bite does.
The scrap check takes five seconds. On critical work, it's not optional.
What you're actually solving for
The goal isn't a particular setting. It's a clean shaving on this wood, today. The correct setup for straight-grained clear cherry is different from the correct setup for figured hard maple with reversing grain. The sequence gives you a starting position. The scrap confirms it.
The experienced user's edge is pattern recognition. They've read enough shavings to know instantly what moved. The beginner builds that recognition by running the scrap check every time. Do it enough and the feedback loop closes on its own.
One note on bevel-up planes
Everything above assumes a Bailey-pattern bevel-down bench plane. If you're using a bevel-up plane, the adjustment system is similar but the cap iron logic doesn't apply. Bevel-up planes control tearout through effective cutting angle, which you set at the grinder, and through mouth tightening. No chip breaker doing work in that design.
What the set is really for
A well-set plane doesn't require much technique. The shaving comes off cleanly because the geometry is right, the iron is sharp, and the depth matches the work. What looks like skill in a hand-plane user is often just setup discipline. The willingness to take two minutes at the bench before touching the wood.
The iron is the instrument. The set is how you tune it.