I've been practicing with apps and can send around 18 WPM fairly cleanly, but my receiving is stuck at about 15 WPM. Learning to receive is by far the hardest part - when starting out, you'll be able to send much faster than you can receive. There's always debate over speed, with many hams happy at 16-20 WPM or slower. But I'd like to get comfortable copying real on-air QSOs. Most messages are sent at 12+ WPM, often 20+ WPM, so improving speed is necessary for proper CW operation. What practice methods worked best for you to break through that receiving plateau?