I sketched out 4 thumbnail sketches in total.

I made the first one intending to take photos and put them together in photoshop. It focuses on the brand name, which takes up the top space. There's wine, cheese and maybe other food on the bottom.

Second one is a mixture of both photos and drawings. The wine bottle and maybe the glass would be photos, and the background with the couple would be drawn. I'm starting to lean towards 50s-40s illustrations and advertising.

Third one would be entirely drawn, no photos. It focuses a bit more on the couple now, but the wine still remains in the centre.  

This is the last sketch I did and the one I ended up using. The smiling woman is holding a glass of  wine. You can't see it very well but she's also wearing some jewelry. The wine is still in the centre.

1. I used Grace Kelly for the face and hair model. She's a 50s actress so I thought she'd fit the style quite well.

2. I looked at a couple of artists for refence. I love the style of vintage american illustration, so I enjoyed learning more about it. This particular artist is Frank McCarthy, who's famous for his western art but has also done some magazine and book illustration.

3. As I said before, I looked at a lot of vintage american adverts. This flickr gallery is a good collection of ads, and this website is, essentially, a very big database of adverts from different decades - also very helpful.

4. I got this image off google. I was looking for 40s-50s style party dresses. Here are the search results.

Once I collected all my reference material, I start the drawing. I used a photo of Grace kelly for the face, and a stock picture as a guide for the hand. The background is a bright yellow, and I put a grainy texture over it, to get the vintage look. I put the sketch layer on top, on 15% opacity, and start blocking in the colors below. Then, once I'm happy with the face, I put the sketch layer below the color layer and draw the hair. After that I add the jewelry, to add more gold to the color scheme. I finish the hand and add the glass of wine. The final step is mainly correcting things and adding more values to the face.

This is the finished drawing, but i'm still going to add some extra textures and text.