Do.

Use exact cells (A1), columns (column B) and rows (row 1) when typing out your formula prompt

Example.

For formulas that will be applied across a range of cells, first create a formula for one cell before dragging the formula across the range

Use the letter of the column ("Column A") to refer to a column instead of header names (ex. "Revenue")

When creating formulas to perform functions like extracting text strings, refer to specific characters rather than general attributes

When creating if statements, make sure to include what the formula should output if the rule isn't met (value_if_false)

When creating if statements, wrap the outputs in quotes

Instead of: [If the cell is less than 25, give the sum of the cells],
use: [If Cell B4 is less than 25, give the sum of Column A]

Instead of: [Divide rows in Column C by the values in Column B],
use: [Divide C2 by B2] and then drag the formula down Column C

Instead of: [Calculate the standard deviation of the revenue column],
use: [Calculate the standard deviation of Column A]

Instead of: [Extract the first name in Cell A4],
use: [Extract the text before the first space in Cell A4]

Instead of: [If B4 is greater than 1, output success otherwise output check needed],
use: [If B4 is greater than 1, output "Success" and if not, output "Check Needed"]

Instead of: [If B4 is greater than 1, output "Success"],
use: [If B4 is greater than 1, output "Success" and if not, output "Check Needed"]