its all about the alt you want to make!

i can tell you that i went the single class (both advent and craft) to 100 first (warrior and blacksmith).....
i was totally new to the game and i found that leveling at least one class to 100 first was a good way to acquint myself with both the game and a wide range of different places in the game. i was introduced to most of the critters and resources in game - in most instances, more than one place for each - and that really helps to level the other classes you decide to take later.

i am currently playing my hatchie, so i can't speak to any other way to develop a multiclass alt....