Absolute Reference Use $ like $A$1 : Lock row & column in copy

Named Range Formulas > Define Name : Readable references

Data Validation Data > Data Validation : Restrict cell input

Conditional Formatting Home > Conditional Formatting : Visualize patterns

Freeze Panes View > Freeze Panes : Keep headers visible

PivotTable Insert > PivotTable : Summarize data quickly

Flash Fill Data > Flash Fill : Automatic pattern extraction

Quick Analysis Ctrl+Q : Recommended charts & totals

AutoFilter Data > Filter : Interactive column filters

CTRL+Shift+L Toggle filters : Shortcut for filter toggle

Ctrl+; Insert today's date : Quick date entry

Ctrl+Shift+! Apply number formatting : Two decimal numeric style