Article · Long read, 18 mistakes plus a pre-ship checklist

18 Common UI Design Mistakes and How to Fix Them

MockFlow · mockflow.com Free Beginner

Use this as the checklist you run before you ship. It walks through 18 specific tells that make an early product feel amateur (clashing colors, inconsistent buttons across screens, weak visual hierarchy, cramped spacing) and pairs each one with a plain fix. It closes with a short before-you-ship checklist, which is exactly the moment most of these mistakes are still cheap to catch.

• Inconsistency is the biggest amateur signal: mixing button styles, colors, and type across screens quietly lowers how much people trust the product.
• Spacing and hierarchy do most of the work: crowded screens usually just need more breathing room and one clear focal point per view.
• Keep it as a pre-ship pass: run the closing checklist against each screen before release, since fixing these later costs far more.