[he takes the brush, noting that it still has some white paint on it. however, instead of making any move to walk over to the ladder and wreck all of her hard work, he simply takes her by the hand and turns her palm over.]

This is how I draw 'em. [the brush hovers over her hand before descending and gently swiping over it in small, circular motions. nothing too big - it's just a small example, after all.] The kind of clouds that show up on a sunny day are always fluffy like this. There's nothing wrong with how you do it, but if you want them to look more realistic and big, just move the brush like this.

[he repeats the motion on other parts of her palm and, before she knows it, she'll have a row of tiny, puffy little clouds dotting her hand.]

See? Easy.