The first and a very common step is to use a volumising shampoo.

Next, you need to add a lightweight conditioner.

Dry your hair with a microfibre towel. But make sure to not rub it.

Next, you can apply a small amount of mousse to damp hair.

For the next step, use a diffuser on low heat.

Divide your hair nicely and make sure that all strands get wavy.

You can also try a curling iron if you want defined waves.