My working method usually includes a complete tonal drawing before I begin any color work. This is where I work out the values and nail down the compositional issues.
When I work in oils I use an underpainting of neutral tones as the framework for the color work to follow. This type of procedure is called Grisaille.
I usually work on several pieces at once. I work with many layers of glazing when working in oils and each work is not always dry enough to work on it day after day.
Working on more than one painting at a time not only allows drying time between layers it allows me time to live with the work for awhile. I judge the color balances on some while I work on composition and tonals on others.
I use digital photography to help me retain the details after the plant's demise. The venation on this orchid is stunning and it's what attracted me to this particular phalaenopsis.I usually start from live specimens though they're frequently not when I'm done with the artwork. This is actually one of the nice aspects of my subject matter. Catching a fleeting moment in time and creating an artwork for the next generation.