Per Jay O'Brien’s suggestion, a word about sourcing materials so you can make your own practice pad:
Materials can be sourced from all sorts of places. The greatest question is whether or not to divide those materials into “purchased new” and “purchased/found used.”
It’s a relatively simple, though often expensive, matter to source materials new from industrial sources — buying new flooring or gum rubber sheets, for example. However, without knowing exactly what’s involved in the manufacture of these materials, we run the risk of only adding to the problem.
But if we source used materials — whether at thrift shops, construction site leftovers, or elsewhere — then we aren’t adding to the sustainability issues often posed by buying new materials.
Also worth considering is your choice of adhesive (to attach the playing surface to the base). Sixty years ago, most commercially made pads consisted of a rubber surface attached to a wooden base, and the adhesive used was often something resembling carpet glue. When the glue’s adhesion strength faded over time, the simplest solution was to simply stretch the rubber taut and use nails or screws in the corners to re-attach the rubber to the wood. (A few of my vintage pads show that this repair worked quite effectively.)
Today‘s adhesives are stronger. The trade off, however, is that the chemicals used in them are also more toxic. (Pro tip: any adhesive whose warning statement includes “use in well-ventilated area” is a sure hint that the stuff may be carcinogenic.) if you choose to go with a more modern adhesive, wear thick rubber gloves and safety goggles and work OUTDOORS.
Lastly, when considering a base material, use real wood or plywood and stay the hell away from MDF (fibrous wood material). The glues used to hold the fibers together give off toxic, smelly gases that can take months to fade. And real wood holds up a lot longer than fiberboard, anyway.
My favorite base recently seen in the wild was a pad made from the seat of an old hardwood dining room chair. The maker simply flipped the seat panel, cut it down to a manageable size, et voila! A nice pad that will last a long time.
(Below: my plant stand pad in action)