Guides

Straight answers to everyday problems, from the people who make the apps. New guides every day.

• SleepHow to Fall Asleep Fast: 10 Methods, Ranked by EvidenceHow to fall asleep fast tonight: 10 methods from 4-7-8 breathing to brown noise, what the research really says about each, and a 20-minute plan to try.
• CardsHow to Measure Card Centering (6 Worked Examples)How to measure card centering at home with a ruler or photo, the formula, PSA, BGS, CGC and SGC limits, and 6 worked examples so you know before you grade.