Toy throwing in 21 month old

[houmousandcarrotsandwich]

When DS is playing he can often throw toys. Sometimes it's mid tantrum, other times just throws toys for no reason. They are not aimed at anyone or anything.
Currently don't use naughty step or anything. I Kind of ignor the naughty & praise the good.
Any ideas how I should be addressing the behaviour?

It's a great game & it gets your attention!

You are perfectly right in praising the good & ignoring the naughty behaviour. Try taking the toy/missile away immediately you see the arm go up & distract him with reading a book or "ooh look at this" something messy/ tasty/shiny/interesting.

Allow him to throw objects outside they soon get to know the difference!

He is only still young & exploring, and pushing Mum's buttons to wind her up is something they do VERY well!

he's probably exploring trajectory, or maybe percussion; have a read here

I wouldn't call it naughty, or winding you up, he's learning about gravity, cause and effect etc

They like throwing as it's a learning process. Can you give him soft balls to throw - make it a game for him?