I guess I have been saying “notice” a lot. Think about it this way: you should look 90 percent of the time and paint 10 percent of the time. The more you LOOK, the more you will see accurately. Then you will be able to create the impression of something realistic.
Quinicridone Gold and Burnt Sienna are the colors of the day! I am using them to add some gold cast to the glass jar, especially at the bottom where the colors are darker because of the way the light is hitting the objects. I used a touch of this color at the top of the jar lid also. Notice the soft edges inside the jar. Some areas of glass will have crisp lines where the shadows are deep, like at the edge of a shape in the glass (notice the letters). Other crisp edges of color can be found around where the light hits the glass directly. All of the other areas will have soft transitions of color by using clear water. Wet edges are soft edges. Dry paper will create crisp edges.
As you look through glass, it will change the values and shapes of objects behind and under the glass. Notice how the jar is a bit darker than the wall.