have seen some of these photos too.. really picture perfect huh? sometimes i'm REALLY wondering if it's unadulterated (digital work). if it is, most photogs still use filters to create the effects like soft filters (for a "dreamy" shot), polarisers for bluer skies and colour filters (some filters make other colours come out more saturated - eg a really green grass field)
i guess it's up to u to decide whether these are "tricks". but i guess u dun really have to bother too much, just look at em, like em and go WOW... is enuff for most, and usually, myself too!