Fast and Frugal Trees (FFTs) are a quintessential family of simple heuristics that allow effective and efficient binary classification decisions and often perform remarkably well when compared to more complex methods. This half-day tutorial will familiarize participants with examples of FFTs and elucidate the theoretical link between FFTs and signal detection theory (SDT). A range of presentations, practical exercises and interactive tools will enable participants to construct and evaluate FFTs for different data sets. Keywords: Fast and frugal trees; binary classifications; simple heuristics; signal detection theory; validity; robustness