+1 for SQL Prompt.
Something real simple that I guess I had never seen - which will work with just about ANY SQL environment (and other languages even):
After 12 years of SQL coding, I've recently become a convert to the comma-prefix style after seeing it in some SSMS generated code, I have found it very efficient. I was very surprised that I had never seen this style before, especially since it has boosted my productivity immensely.
SELECT
t.a
,t.b
,t.c
,t.d
FROM t
It makes it really easy to edit select lists, parameter lists, order by lists, group by lists, etc. I'm finding that I'm spending a lot less time fooling with adding and removing commas from the end of lists after cut-and-paste operations - I guess it works out easier because you almost always add things at the end, and with postfix commas, that requires you to move the cursor more.
Try it, you'll be surprised - I know I was.