I'd get a soup plate and then slide the glass very carefully over to the edge of the table, and let the water run into the soup plate - it doesn't have to run onto the floor.
母は台所でせっせと料理しながら歌を口ずさんでいた。
Mother hummed to herself as she went about her cooking in the kitchen.
兵士達は警戒しながら国境に向かって進んだ。
The soldiers headed for the frontier with caution.
兵士たちは警戒しながら国境へ向かった。
The soldiers proceeded to the frontier with caution.
浜辺でおしゃべりしながら散歩するのが好き。
I enjoy walks and talks on the beach.
彼女は涙を流しながら答えました。
She answered with tears.
彼女は涙を流しながらその歌を歌った。
She sang the song with tears running down her cheeks.
彼女は頬に涙を流しながら彼の手紙を読んだ。
She read his letter, with tears streaming down her cheeks.