keep in mind:记住
Keep in mind that you'll have to practice economy.
记住要厉行节约.

for a change:为了改变一下,为了换个口味
Let's go to a movie for a change.
我们换个口味,去看场电影吧!
Let's eat Italian food for a change.
让我们换个口味,吃意大利菜吧!