Power Query - Best Practice to Reduce # of Steps?

Hi DKoontz 

Reordering columns n times makes no sense from an efficiency perspective. You should re-order only once i.e. at the end of your query

Re. renaming columns it depends what your query does. Assume you have a table with [Column1],[Column2]. If you rename [Column1] and later delete/remove that column, for sure it makes no sense to rename it. On the other hand, if in one step you rename [Column1] and in another step rename [Column2] (as long as you're no going to delete any of those columns later) this shouldn't make a differerence from a performance perspective (vs. renaming the 2 columns in a single step)

Regarding type changes it depends on the scenario as some transformations/operations "loose" columns types and you might want/need to re-type some columns before moving forward
A common "mistake" is to add a custom column without typing it then to add a change type step: If you add a column theoritically you know its data type so type it when adding that column

Couple of other points:
- Other common "mistake": a step that changes the type of [Column1] followed by a delete/remove [Column1] when [Column1] isn't involved in other calc. in the meantime
- As a general rule: get rid of the columns and rows you don't need as soon as possible
- The number of steps of a query doesn't necessarily correlates with its efficiency
- There are non-obvious things that only MSFT people know. E.g look at Curt H. reply to https://social.technet.microsoft.com/Forums/en-US/30da8f81-a3a9-4924-b54c-3007f508b24f/tableaddcolumn-tableremovecolums-vs-tabletransformcolumns-from-performance-point-of-view?forum=powerquery