Once my puppies are weaned and about 4 week old. I place them in a puppy pen or exercise pen that
has 8 panels. I take an airline crate and take the door off  and the top off and just use the bottom.

 As you can see there is news paper down all over for puppies to go the bathroom on. Also
the puppies have blankets in the airline crates and they always seem to sleep in the crate.
Once they get used to sleeping in the crate I placed the top back on. To make sure the
puppies sleep in  the crate at first I turn the heat down in the room and take a heat lamp
and place or over the crate so the puppies are just a little warmer there than they would
be sleeping on the plain floor. Once the puppies are used to sleeping in the crate for a week
I placed the top back on. I always leave the door off. Along with blankets the puppies have
their toys  in the crate with them. The toys are explained in a article written last month, 
"How to ease separation anxiety in puppies".  By getting the puppies  to sleep in a crate

 
before they go their new home, you are helping get the puppy crate trained before
they leave you. By making sure the new puppy owner takes home a stuffed toy
with the litter scent on it, you are doing everything possible to make the transition
from your home to the puppy's new home is as easy as possible.  It does not matter
who you sell to nobody likes to listen to a new puppy scream all night.

This a picture of Renegade's Road Dog at 5 weeks of age as you can see he is very
happy to lay in the crate and cuddle with his stuffed toy.