Water pops up a lot in my work: rivers, oceans, and lakes often can be rendered with smaller generic waves/ripples. Stormy seas, waves and white-caps are a different beast.

Thinking BEFORE you paint can save a lot of time. While most things can be painted with standard brushes, being creative with custom brushes often is more efficient and gives a better result - providing you still add some detailing...

When I'm in the "unhappy" phase with my art it's usually because there aren't enough values painted. Everything looks flat. Here's my cheat to add more contrast fast...