Yes, if the .xinitrc file doesn't exist, you will have to create one (and make it executable - it is in fact a shell script). And you will have to do a little research into how exactly it works, because it is not entirely newbie friendly. But it is the way I've always done my X stuff.
I'm guessing that .xsessionrc is the new, newbie-friendly-Linux way of doing the same thing.
And some folks need to stop being fanboys and see the forest behind the trees.
(One of the best lines I've seen on this board lately)