small; fine; minute
stingy; cheap
「細い」 has another reading with different meanings.
thin; slender; fine
字がこまくて読みにくいなあ。
The writing is so small it's hard to read.
こまい部品をピンセットで組み立てた。
I assembled the small parts with tweezers.
こまいところまで気を配るのが彼女のいいところだ。
Paying attention to the smallest details is her good quality.