Present wish
You need money to buy new clothes.
I wish I had money to buy Balenciaga's new collection.
You got a 0 (zero) in your English exam.
I wish I had studied harder.
Your colleague has a new computer. You envy him/her.
I wish I had a new computer.
Your brother/sister fought at school.
I wish I had been there to stop/help him/her.
You have a chance to change one thing about your country.
I wish there were no more people living in the streets.
Your friends went out to a party. They haven't invited you because last time you drank too much and misbehaved.
I wish I hadn't misbehaved. or I wish I hadn't drunk so much the last time I went out with my friends.
Your handwriting is terrible.
I wish my handwriting was beautiful.
Your parents forgot your birthday.
I wish they had not forgotten my birthday.