Left woman radical - pictograph of a kneeling figure with folded hands. Indexes 嫖 in the female-related family with 妓 prostitute, 娼 brothel-woman, 婢 maidservant. 嫖 names the act of paying for sex - a blunt classification baked into the script.
Right side 票 supplies the sound - piào shifted to piáo with a regular tone change. Same phonetic in 漂 to float, 飘 to flutter, 瓢 gourd. Its 'light, fluttering' image quietly fits the transient nature of the transaction this names.