These sketches are inspired by Tia Boon Sim's sketches. She likes to prepare her watercolour paper by splashing them with paint. Usually, she has several pieces that are prepared days in advance.

You can splatter paint anyway you like. For wet washes, you can charge in with additional colours to let the colours blend smoothly.

The splashes certainly make the sketches look more lively.

This is the reference photo.

Here's a video demo of how I created the sketch at the top.