Choosing the right word: Guidelines for our global audience?

[Kate Wilcox]

Geoff Hart responded:

<<The best advice I can give you is to find a colleague in the second  
country (here, India) who can provide reliable advice, and pay close  
attention to their advice until you've learned the most common tricks  
and traps. Think of this as an exercise in localization...>>

That's good advice for projects that are localized. However, we have
only one version of English manuals. We don't currently localize for the
UK, India, and the US, and it's not clear which is the larger audience.
Since writers in India and the US often have different opinions when it
comes to choosing the right word, how do you determine which words are
right?

As a manager, how would you decide and how would you explain that
decision to writers whose opinions differ? 

-Kate