1. SUMIFS: sum with several conditions, =SUMIFS(C:C,A:A,"East",B:B,">1000");
  2. COUNTIFS: counting with conditions;
  3. VLOOKUP: vertical lookup, =VLOOKUP(F2,A:D,4,0);
  4. XLOOKUP: reverse lookups and built-in error handling — the modern replacement;
  5. IFERROR: hide errors, =IFERROR(A1/B1,"-");
  6. TEXT: format output, =TEXT(A1,"yyyy-mm-dd");
  7. LEFT/RIGHT/MID: extract substrings;
  8. CONCAT / TEXTJOIN: join cells, TEXTJOIN adds a delimiter;
  9. SUMPRODUCT: weighted and conditional maths;
  10. INDEX+MATCH: lookup in any direction.

Tips

Convert ranges to tables (Ctrl+T) so formulas fill down automatically; whole-column references reduce maintenance.