Use the HTML5 Micro Expression Trainer at 25% speed. Focus on one emotion pair that confuses you (e.g., fear vs. surprise).
However, if you work in law enforcement, security, or clinical psychology, you need the paid METT (approx. $100–300) because it uses spontaneous, high-speed expressions filmed at 500fps. Free tools are training wheels; the paid version is a racing bike. micro expression training tool free
Use the Ekman public test to see where you stand. Then study the facial action coding system (FACS) basics via free PDFs (search "FACS quick reference guide"). Use the HTML5 Micro Expression Trainer at 25% speed
Move to 75% speed. Then switch to YouTube clips of real press conferences (e.g., politicians answering tough questions). Pause after each sentence. fear vs. surprise). However