[Dave Paine]

In my case, it was pieces of wood I had available. "Construction lumber" which was a softwood, likely a spruce or pine. Not as tight a grain as I wanted, but it was whatever was in my scrap pile.

I glued up pieces to make thicker blanks for practice turning beads and coves.

 

[Dave Paine]

+1 with duncsuss. I prefer solid wood to plywood, especially if construction grade plywood with thick layers, voids and knots. There will be tearout since more end grain exposed in alternate layers.

I glue up straight grained 2x4 pieces to make 4x4 sections for practice. It may feel large but after some practice you will see how fast you turn this down.

I found it easier to practice beads and coves on the larger X section than smaller X section. You will have your share of catches, then more turning down to remove, etc.