CD's and no-more-nails* have a natural affinity. I've seen articles sanding CD's then flocking them. Too much for me, plus there's still the hole and it's only one sided. Double thickness of NMN also means easier to pick up.
Tear some scraps of cornflakes cardboard, cover both holes (shiny side of cardboard down) at same time with minimum NMN. Thump. Cover one side with good splodge, leave to dry. Paint or flock.
These are about a year old with no attempt to keep fresh.
I've always used ply but without the need to have measured bases these days it's a bit, well, wooden. I admit it's still the best method for fragile models like walkers.
Tried using shard of CD to create a shadow-base for a grav or ground effect vehicle, I like the effect, but cutting up CD's is a pain. I hate having a nice textured and decorated base, then it's in the wrong environment and it looks naff.
I'm sold now on waste plastic from food packaging plus a layer of NMN. If you use toy cars** a few drops of superglue does wonders. For dirt roads I run the vehicle up and down before gluing to produce tracks and dirty up the tyres.
Here's a thickness comparison. .8mm ply and sand/pva vs plastic and NMN. Not only is this method cheaper, it's a lot quicker. Cut, splodge, press. Paint underside. Glue when dry, paint.
Very thin plastic sandwich and a thin layer- you have a modern road surface, but you have to wash the plastic first, and it can curl where a single layer base doesn't. Do everything wet and be prepared for a mess.
This method also does road damage, cut and peel back the top layer.
Plus, try this shadow method as it goes anywhere. Just offset base and highlight the other side. The main difference is that the surface method the vehicle is in, the shadow method it is on.
Be prepared to change your mind. Wheeled and tracked AFV's, construction vehicles go into the ground, look wrong with just a shadow- unless you want them for urban, in which case I'd suggest a vey minimal base.
Watch out for texture! Cake packaging makes perfect 15mm cobbles. Watch this space for figure bases and lamp posts. I'm thinking a roofing nail topped by either a toothpaste top or rawlplug. If you've got any ideas, please post here! Now if I can only get it to photograph-.
*Abreviated to NMN. Actually I use the generic 151 product Hard as Nails available from the Poundshop in the UK. I get through 1 tube a week in the slack times and 1 every 2-3 days when in full flow. I could give it up, couldn't I?
** I'm always collecting these. Now they're filler or A-B movers that get thumped. Blue ink on the windows to disguise the lack of driver, tone down the paintwork and dirty up. Jobs done.