To consolidate data from multiple Excel files into one sheet, consider the following steps:

1. Create a list of columns that need to be amalgamated.
2. Create a new spreadsheet containing the same columns from the list, plus any additional columns.
3. Copy data from each of the original spreadsheets one by one, pasting it into the new spreadsheet.
4. Repeat step 3 for all the original files.
5. Check that all columns have been correctly filled and any additional columns are correctly formulated, if any.
6. Once the new consolidated sheet contains all the data, save it.