I love to work from life; it is a enjoyable experience to set up a still-life using some of my possessions that I treasure. I especially like painting from flowers from my garden. However, sometimes you can’t finish a painting because the flowers wilt or the fruit goes bad. This is when I find it useful to take a photo of the still-life at the beginning of the painting, so when this happens I will have a trustworthy reference to follow.
I find it important to shoot my photos at this time because if I have set it up by a window I need to have the light exactly the same as it was when I first started painting it.
If I am taking photos in my garden it is best to shoot in the morning or late afternoon hours. These times of day will provide me with the very best shadow angles. I love to take lots of close-up photos of the flowers, the leaves and stems. Move in on anything you think will help you paint and take a photo!
Photograph flowers from all angles so you will have a nice variety to paint from. You can pick and choose which ones will make a beautiful arrangement.
I have plastic photo storage boxes where I store all of my reference photos. I put them into categories so they are easy to find.
The only problem is that painting from a photo often gives results that are not the same quality as you get when you paint from life. To do so you need a lot of experience of painting from life, you need to know how to render something with the basic values under various lighting conditions and get accurate color, then you can fill in what is missing from the photos.
It is hard to make something on a flat piece of paper look 3D. It is much easier to do this from life. Your only reference being photo will not be accurate, so you need to draw on your experience and imagination,
I have found it actually much harder to paint from a photo than life. The photo will distort varying degrees of the drawing, the values and colors will not be accurate, they may look good but not actually how the human eye sees it.
Often the depth is lost and so you have a hard time deciding what things are in front of what.
If you only have a photo to paint from then you may have no alternative, but if at all possible choose to paint from the actual subject rather than a facsimile of it, in the end you will have a much more lively painting!