"get comfy" is correct and usable in written English.
You can use it when you want to encourage someone to make themselves feel comfortable. For example, you could say "Come on in and get comfy!".
Don't get comfy, Beijing.
Get comfy, put the kettle on and tune in.
"Gonna get comfy and cozy, like this my home," he replied.
Republicans could either get with the program or get comfy with their image of being woefully out of touch.
If you wake up early and just can't get comfy, get that "just into bed" feeling by flipping the pillow.
This is followed by Die Walküre (5hrs 50minSiegfriedried (6hrs) and finally Götterdämmerung (get comfy: it lasts 6hrs 30mins).
In our conversation, he denied that he "sets pitchers up" but also said that "sometimes you give a pitcher confidence so they can get comfy".
Wide door sills must be negotiated before you get comfy in the one-piece carbon-fiber buckets covered in Alcantara suede.
But you'd better get comfy soliciting money, too, or your small arts organization will go the way of many others in this economic downturn — and I don't mean to Lincoln Center.
He has a way of telling you, at the start of every film: settle down, get comfy in your seat because very soon, you'll be on the edge of it.
But while delegates fill up on free jellybeans and get comfy in their seats, the students they represent are scattered around the country revising for exams, writing dissertations or having an Easter lie-in at home.
