Not all details in a reference are equal. Some define the subject; others are noise. The skill is knowing which is which before you start drawing.
I call this the reference hierarchy: a mental ranking of visual information from essential to expendable. Without it, you'll spend equal effort on a nostril and a nostril shadow, and the drawing will suffer for it.
Most references follow the Pareto principle: roughly 20% of the details carry 80% of the visual weight. That 20% includes the big shape, the main value pattern, and the key landmarks. The rest is texture, minor edges, and subtle gradients that rarely matter unless you're doing hyperrealism.
Your first job is to identify that 20%. Squint at your reference. What survives the blur? Those are your top-tier details. Write them down or sketch a tiny thumbnail that captures only those.
Don't rank details by how interesting they look. Rank them by what they do for the drawing. A highlight on a cheek might be beautiful, but if it doesn't describe the form's turning edge, it's lower priority than the shadow that does.
Ask: does this detail explain structure, or is it decoration? Structure wins. Decoration can be added later if there's time and if it serves the whole. Most of the time, it doesn't.
I sort reference details into three tiers:
When you trace or draw, work in order: Tier 1 first, then 2, then 3. If you run out of time or patience, you'll still have a solid drawing.
Sometimes a Tier 3 detail becomes Tier 1. A single strand of hair crossing the face might define the expression. A texture might be the subject. That's fine—just be intentional. Know you're breaking the rule and why.
The hierarchy is a tool, not a law. But having a default ranking keeps you from getting lost in the weeds.
When you trace, you're forced to make choices about what to include. The hierarchy helps you decide fast. With a tool like EchoDraw, where you see a semi-transparent reference over your paper via your phone's camera, you can toggle the reference's opacity to check your progress against the tiers. Start with the reference faint and focus on Tier 1. Then increase opacity to check Tier 2. Leave Tier 3 for last, if at all.
This approach also prevents the common tracing trap of copying everything equally, which flattens the drawing and kills spontaneity.
Pick a reference with clear structure and some texture. Set a timer for 10 minutes. Trace only Tier 1 details. Then 10 minutes for Tier 2. Stop. Compare with the reference. You'll likely find the drawing reads well even without Tier 3.
Do this regularly, and you'll train your eye to rank automatically—a skill that transfers to drawing from life, where you have to prioritize in real time.
Grab EchoDraw and turn any photo into a live tracing guide.