Thesis needed custom PCB (sensor breakout + ESP32 socket). KiCad seemed obvious choice. 3 revisions later, here's what I learned.
Trip 1: Footprints from random library mismatched actual part. Always verify pad pitch vs datasheet before ordering. Bought 20 wrong-footprint resistors.
Trip 2: Forgot ground pour on bottom layer. Board worked but ESP32 WiFi range was terrible. Re-pour fixed.
Trip 3: DRC warnings ignored 'because the board looked OK'. JLCPCB rejected the file on first submit due to silkscreen overlapping pads.
For first PCB: do the KiCad tutorial fully, don't skip DRC, double-check footprints against datasheets. Worth the extra hour upfront.
KiCad veterans: anything else first-timers miss?