I use a crate for my 15 week old. It is a comforting safe place for them - their own little den. I am a big believer in crates - like a play pen & baby bed rolled into one.

The crate should not be too big - giving him too much room gives Dudley a place to potty too... Smaller crate he won't do that unless he can't wait any longer.
Chloe sleeps in her's... at night, or during times I have to be away OR when she is on my older corgi's last nerve

I put her in puppy time out. I leave her crate door open the rest of the time and she goes in and out all day.
I have a bed with soft towel for her to sleep on and a washable rug under her feet. Also keep a larger area rug under the crate so it won't mar the kitchen floor. Inside her crate she usually has a soft toy and a compressed bone to chew on. If I am away for a few hours I put a water bowl inside too.