You don't need a special, fancy basket to proof bread. I had this bread basket from somewhere (has since disappeared at some event) that I sometimes proofed bread in. The key is using a tea towel dusted with rice flour.
Why a basket instead of free form, letting it rise the entire time as a round ball? Well, some breads just don't rise "up". They are more likely to flatten out and turn into a flattish disk instead of a roundish, full ball. Every dough behaves differently. For the Pain de Campagne bread I make, it just can't hold up to rising on it's own without a basket. Other breads can. You have to experiment or follow the guidelines in the book
To proof bread in a basket, you treat it as if you were going to do it free form. You have to make the dough into a ball and tighten it to create tension on the top - keeping the seam tucked under. When you put it in the bread basket, you put the seam on top so that the unblemished side, the side with tension is forming along the basket walls. Hmm... showing that might need to be another post!
So, here it is proofing in a basket with a rice flour dusted tea towel. I have designated this tea towel for proofing only. You can also buy liners specially made for proofing baskets, but I don't see why.
As you can see, it's an ordinary, cheap basket. and a plain cotton, thin tea towel.
And the rising dough inside:
Now, the tricky part is getting this dough that is proofing onto the baking tray/cookie sheet. The best way I've found is to place the tray upside down (with parchment paper or with a silicone baking mat to prevent sticking) over the basket and then flip the whole thing over. This keeps the dough from getting too disturbed and deflating. Like this:
Now remove the basket. As you will see, you still get the design of the basket on the dough.
Now, simply remove the linen. It won't stick as rice flour really is like teflon.
Pain de Campagne won't do that if slashed on top. Or at least, it never has for me.
Here is the slashing: