A pinch (a small amount that can be picked up between the fingers); a tiny quantity.
スープにひとつまみの塩を入れて味を調えてください。
Add a pinch of salt to the soup to adjust the flavor.
その薬は粉末なので、ひとつまみ取って水に溶かしてください。
Because the medicine is a powder, take a pinch and dissolve it in water.
経験はわずかだが、ひとつまみの自信はある。
My experience is small, but I have a pinch of confidence.
An easy victory; something or someone easily overcome (figurative).
相手は初心者ばかりで、試合は一撮みだった。
The opponents were all beginners, so the match was an easy victory.
その会社の新製品は市場で一摘みの存在だとは言えないが、注目は集めた。
You can't call that company's new product insignificant, but it did attract attention.