When I started playing there was no official scenery. The Games Workshop scenery you can get these days is amazing stuff and lets you build some amazing tables for battles. Definitely a step up from the scratch build stuff we made back in the day,
Behold the Chaos Space Marine bunker fortification with added spikey bits. Clearly I didn’t fancy painting black and yellow danger chevrons or chequerboard pattern, which was unusual given how prevalent these were at at the time!
Scratch built trees made from paper clips wrapped in masking tape with wire wool and green scourer/scotchbrite pads cut for leaves.