First of all good one Pinal,

I can think of following few points to add as 15th.

1. if using idexed, look closely at your where statement to make sure columns in where clause are properly ordered.
2. Work with Linked servers whenever possible.
3. If working with large databses use NOLOCK in queries.
4. Use of Begin Tran and Commit Tran would help in large updates on production database.

Pinal,
Please let me know if any one of above points seems incorrect.

Thanks,
Shruti

Great Comment Shruti.

3 - I have debates with myself over this one. Yes, it makes sense from a data-integrity point of view, but at the same time it encourages code duplication, which is a very bad thing in my opinion.

9 - I disagree. CAPITAL LETTERS are difficult to read. The only reason SQL used this to start with is because syntax highlighting hadn't been invented yet. Now that it has, there's really no reason to use them anymore.

11 - Very much disagree. SP's have no performance or security advantages over ad-hoc queries, and creates codebases which are a nightmare to maintain.