It didn't fit quite right, so I don't think I'll take it.
It doesn't fit the way I like, so I think I'll pass.
ーIt didn't fit quite right, so I don't think I'll take it.
「着た感じがしっくりこないので結構です。」
didn't fit quite right で「しっくり合わなかった」=「着た感じがしっくりこない」
I don't think I'll take it. は、お店で試着した洋服を買わない時によく使える言い方です。
ーIt doesn't fit the way I like, so I think I'll pass.
「着た感じがしっくりこないので、結構です。」
doesn't fit the way I like で「私の好きなように合わない」=「着た感じがしっくりこない」
I think I'll pass もこのシチュエーションでよく使います。
ご参考まで!