Coding standards and practices
I’m in a position where I once in a while find my self maintaining parts of _really_ old code. The code that have been revisited multiple times over the years by multiple developers. At the times like those I really hope that the coding style guide practice would had been around from the day one.
Every developer will have their own style of coding at heart which they have learned and generated over the years. I think that there shouldn’t be the ‘one standard to rule them all’-style as it might be too heavy to follow and therefore would cause bad spirit within the team. I’d rather see that people can share and learn best standards by collaborating when writing new or old code.

I have favored the formal code reviews but now that I’ve been involved in an agile team I feel that these reviews wouldn’t ‘fit in’ to the development flow. In my opinion the best feedback and share of knowledge is achieved by collaborative development. Whatever this is pair programming or collaborative modeling or just ad-hoc debugging with colleagues.
One of the greatest books covering this subject is the Code Complete written by Steve McConnell. The good thing about the book is that it doesn’t just point out some common guide lines for code layout but it also digs deeper for explaining a good code structures for very readable and maintainable code. I’ll encourage every developer to read it.