In the early part of the game, sheer intimidation works, you want a
continent, put all your armies in it. In a continent like South America
or Australia this is very effective, especially if you own more than 50%
of the countries. Now starts your reasoning with other players that own
countries, convinicing them that their armies will be wasted blocking
you, and that if they don't block you, that you'll back them up in
another border. If they block you, take some of your armies and place
them to block them in attempt to chance their minds. This is all done
before the first dice are thrown. You can victory at the beginning
without even attacking.
As the game progress, you will probably be required to make pacts and
treaties with other players, but be thinking always of the outcomes
because as you nail one player to