Using were instead of was makes a sentence more formal e.g. I wish I were a little taller.
I wish I was rich. I wish I had a car and owned a house in a good neighbourhood.
I wish I went on holiday more often.
I wish I ate hot meals as I don't get the opportunity to do that now.
We wish he knew how to skate.
They wish they kept some animals as pets.
She wishes it would stop raining.
He wishes he could play in the natch next Saturday.
They wish they could go on a trip in March.
I wish he would decide what he wants to do.
I wish they would fall in love with each other.
Don't you wish your neighbours could be quiet during the evenings?
I wish he would buy me that ring.