Don't be skimpy with your skin lotion. Put on lots.
It's better to use lots of lotion for your skin rather than cheaping out.
この場合、次のような言い方ができますよ。
ーDon't be skimpy with your skin lotion. Put on lots.
「化粧水はケチらないでたくさんつけて」
to be skimpy with ... で「…をケチる」
ーIt's better to use lots of lotion for your skin rather than cheaping out.
「ケチらないで肌にたくさん化粧水をたくさん使うのが良い」
to cheap out で「ケチる」とも言えます。
ご参考まで！
It's important to use a lot of cosmetic lotion without being stingy about it.
It's better to put on a lot of cosmetic lotion without worrying about how to use it economically.
ご質問ありがとうございます。
① "It's important to use a lot of cosmetic lotion without being stingy about it."＝「化粧水はケチらないで使うことが大事です。」
② "It's better to put on a lot of cosmetic lotion"＝「化粧水はいっぱいつける方がいいです」
"without worrying about how to use it economically."＝「節約しようと心配しながら使うよりも。」
ご参考までに。
カナダ 
アメリカ合衆国 
