Probably find a way to waste it without affecting anything.
I make 1000€ per month more than 5 years ago. Didn't affect anything. You always seem to increase your monthly expences with equal ammount. Buy slightly better clothes, more expensive food, get a new pet, etc. and it all just disappears.
We already had a pet, so it was to make the pet happier, but it was a bad example.
For example in food you can buy the cheap tortured chiken or organicly grown outdoor chiken. It's still the same chicken. You just feel a bit better when you think about it.
Little improvements like this are a money sink and you can easily sink a 1000€ per month without really changing you everyday life.