The fastest way to make an interface look amateur is to mix icons from five different libraries. One is bold, one is thin, one is decorative, one has detail that vanishes at small sizes. This is not purely aesthetic — consistency reduces the time users spend decoding a screen.
Choose one style across the product: outline or filled. Do not mix them except to signal a specific state, such as the selected item in a bottom navigation bar. If you truly need two styles, write the rule down for the team: filled means active, outline means inactive.
Three sizes are enough: 16 pixels for small elements, 24 for headers and menus, 32 for larger surfaces. Never scale a 16-pixel icon up to 32 — the strokes go fuzzy. Use SVG and draw the original size properly.
First, relying on the icon alone with no label. A share or save icon is not obvious to everyone; a word resolves the ambiguity instantly. Second, coloured icons with no reason in an otherwise grey interface. Third, ignoring dark mode, so black icons become invisible.
One point often skipped: alt text and screen-reader descriptions. An icon without a description is a closed door to a screen-reader user. At Q8DM we treat that as part of the design, not a later add-on.
Consistency is a habit, not a one-time task. Create one folder named project icons containing only approved files; anything new enters through review. That folder becomes the single reference, and a new designer learns the rule without a long briefing.
Standardise naming too: user-profile and trash-delete beat icon-1 and icon-2. The payoff shows up six months later when you are hunting one icon among a hundred files.
Take your main screen and place the icons side by side at 24 pixels. If one looks heavier or lighter than the rest, or if you have to lean in to tell what it depicts, you have a consistency problem. This test reveals more than reviewing design files ever will.
Icon consistency is not decoration; it is a form of clarity. One style, one grid, one stroke weight, applied everywhere. Q8DM has provided software, design, and training in Kuwait since 1998, and interface design is core to that work.
Want a review of your interface design? Get in touch at q8dm.com.