I'm a big fan of pure arties, but I've seen and heard of 3 cool multi-class builds.
I was toying with the idea of a bladeforged that is 2 levels paladin, 2 levels rouge, and the rest arty (since you have to take the 1st level as pali).
A player named Tagyis on Sarlona recommended 2 levels Favored Soul, 2 rouge, and the rest arti. And another player from Sarlona, Picu, suggested a similar build with the classes being bard, rouge and arty. Those both sound like fun to play!
Although I like my arty to be pure I'm pondering a multi-classed bladeforged arty.
Just some ideas in case you want to go with a different type of arty build.