Why does my drawing look wrong even though each part looks right?

Relationship errors rather than shape errors, the checks that expose them, and the habit of working the whole drawing at once.

Difficulty: beginner
Time: 30 min
Read: 3 min

Short answer

It is almost always relationships rather than shapes — a feature slightly too big, or in a position a few degrees out. Measure everything against one unit, check angles against vertical, and look at the drawing in a mirror or upside down to break recognition.

A drawing where every element is individually well observed can still look badly wrong, because the eye judges a picture on the relationships between parts, not on each part in isolation.

Step by step

Accept that it is a relationship problem.If each element looks acceptable alone but the whole does not work, the sizes and positions relative to each other are off. That is a measuring problem, not a drawing problem.
Pick one unit and measure everything against it.The head, the width of the mug, the length of a forearm. Hold the pencil at arm's length with your thumb marking that unit and count how many fit into every other dimension.
Check angles against true vertical and horizontal.Hold the pencil up vertically beside the subject. Most drawings that feel wrong have all the shapes right and several of the angles a few degrees out.
Check alignments.What is directly above what? Drop an imaginary plumb line from one feature and see what it passes through. Comparing that with your drawing exposes displaced elements immediately.
Look at it in a mirror.Reversing the image removes familiarity and errors jump out. It is why artists have used mirrors for centuries and it takes two seconds with a phone camera.
Turn it upside down.Same principle. Your brain stops recognising the subject and starts seeing shapes and relationships, which is where the error will be visible.
Photograph it and look at it small.A small image loses the detail you have been absorbed in and shows the overall pattern. Errors of proportion are obvious at thumbnail size.
Work the whole drawing at once.Bring every part along together rather than finishing one area before starting another. Finishing an eye before placing the other one is how faces end up asymmetrical.
Check the negative shapes.The gaps between and around things. If those shapes match the subject, the positive shapes must too, and you have no stored symbols for them to interfere.
Be willing to move a big thing late.Rubbing out a well-drawn feature that is in the wrong place is uncomfortable and it is usually what the drawing needs. Moving it 5mm can fix everything.

Tips

Phone camera, flip the image. The fastest error check there is.
Measure against one unit rather than judging each length separately.
Bring the whole drawing along together instead of finishing one area at a time.

Common mistakes

Finishing one part before placing the rest — Every later element then has to fit around a fixed one, so errors accumulate outwards and the drawing runs out of space or goes lopsided.
Refusing to move something that is well drawn — The quality of an individual passage counts for nothing if it sits in the wrong place. Almost every experienced artist erases good work to fix a relationship.

If it doesn't work

Face looks subtly wrong

Cause: Features individually right, spacing wrong — Fix: Check eye line, the distance between eyes, and the vertical alignment of nose and mouth against a plumb line.

Drawing runs off the page

Cause: Started with detail rather than overall proportion — Fix: Block in the extremes of the subject lightly before anything else.

Figure looks squashed or stretched

Cause: Unit measurement not applied consistently — Fix: Use head heights as the unit and count them down the figure.

Cannot see what is wrong

Cause: Too familiar with the drawing — Fix: Mirror it, turn it upside down, or look at it as a small photo.

Questions people ask

Why does flipping the image work?

Your brain has learned to read the drawing as the thing it represents, which suppresses errors. Reversing it breaks that recognition, so you see shapes and relationships again.

Should I use a grid?

A grid is a useful training aid and a legitimate tool for accurate copying. It does not build the measuring skill, so use it alongside eyeballed measurement rather than instead of it.