I read an article about collocation which includes an example:
We can say highly sophisticated, and we can say extremely happy.
highly happy and extremely sophisticated would be wrong.
Because the basis of collocations is probabilistic, based on the colloquial, and the rules are arbitrary, it seems there is not actual 'getting it right', but rather there would mostly just be a 'sounds okay.' Note the computer example (powerful vs. strong computer); it's not that strong computers don't exist- they are just normally referred to as powerful.
Since this isn't idiomatic (ie, a static, limited case use), the problem with giving hard, fast rules is that they would likely be localized or a compendium of adjective/noun combos you would need to memorize.
For consolation, someone from the west coast of America might says something is 'totally awesome' and someone from the Atlantic northeast might says that same thing is 'wicked awesome'; but they'd both sound like fools because everybody knows that something is 'freaking awesome' here in Ohio.
Google is your friend here. "Highly happy" returns 74,000 hits (many of which refer to a book with the phrase in the title), while "extremely happy" returns over 6 million. So the latter is clearly the stronger of the collocations.
Alternatively, you could use a collocation dictionary such as those published by Oxford or LTP.
I agree with mfg's answer; most of these are convention and there are no good rules. However I wanted to add that in some cases you can eliminate certain combinations that don't make as much sense.
highly sophisticated
In this case things that are more sophisticated are often seen as better or more "advanced" and thus "higher" than the base, simple, unsophisticated things. It makes sense to "order" the sophistication from high to low.
extremely sophisticated
I think this is a perfectly acceptable way of expressing the thought.
highly happy
In this case I would say happiness is not ordered and more emotion is not necessarily better than less. However this is not a hard and fast rule, more of a guideline (the phrase highly happy might sound a bit odd to me, but I probably wouldn't consider it a mistake).
So I think you have a fairly high level of freedom to choose your modifiers, and as long as you don't pick one that is really inappropriate, people will understand you, and probably won't think anything worse than "This person is from out of town".
We can say highly sophisticated, and we can say extremely happy.
This has to do with specificity. "High" is more specific than "extreme" and "sophisticated" is more specific than "happy".
"Extreme", being the looser, can go easily with either.
"Highly" has connotations of superiority (compare "extremely little" vs. "highly little") so this fits well with "sophisticated" (you would only say "highly inferior" if you were mocking something, being ironic).
As for "highly happy", I guess that would be a suitable combination only if someone was happy because of their "height" (status). It's phonetically uncomfortable and I guess that's the main reason it doesn't seem right.
