Answer:
Using "fewer" properly:
I need to eat fewer sweets if I want to lose weight.
There are fewer people in the office today than usual.
The store had fewer items on sale than I expected.
We need to use fewer plastic bags to reduce waste.
I've been drinking fewer cups of coffee to avoid getting jittery.
Using "less" properly:
I need to spend less money on unnecessary purchases.
There is less traffic on the road during holidays.
The movie was less interesting than I thought it would be.
I try to consume less sugar for the benefit of my health.
We need to use less water to conserve resources.
Using "good" properly:
This cake tastes really good.
Her grades have been consistently good this semester.
The restaurant has a good selection of vegetarian options.
It's important to do good deeds for others.
My new job has been a good opportunity for me.
Using "well" properly:
She speaks English very well.
I slept well last night and feel refreshed today.
The team played well and won the game.
She is doing well in her new business venture.
He cooks very well and makes delicious meals.