All through my childhood I remember Goblin Green bases and flock but my hobby budget was so limited that I just didn’t want to shell out for it, so always did what he ‘starter paint set’ suggested and mixed white and dark angels green to horrific results
For my Warhammer undead I used a cheap grass flock and thought I was being clever by putting patches of brown in (believe it was the Woodlands scenic stuff, I bought it because it was significantly cheaper than GWs in house stuff).
Now I generally ‘go with the flow’ for basing but for the few 40k things I still paint, it’s Bestial brown (or equivalent) then a ‘special mix’ of differing brown flocks, sometimes with patches of green if I’m feeling vibrant. Very, very occasionally I’ll put something additional on, but generally I’m not interested in bases or basing. Massive pet hate for me are those miniatures where the model is 50% base, or a bit of ruined building that miraculously moves with the miniature!
The only bases I’ve made a bit of an effort with are Mantics TWD ones. I use grass tufts and the textured earth stuff.