Here's a set of quick studies I've done in recent years. These are, typically, small-sized oil paintings done in less of one hour. I use a variety of supports for doing them, such as wood panels, cardboards, or paper.
The Tagus river at Vila Nova da Barquinha. Oil on wood, 15 cm x 23 cmSt. James's Park, London. Oil on wood, 15 cm x 21 cm
You can find the vast majority of my paintings in my Facebook page