First of all you should not assume every color photograph can be converted to a "successful" B&W photo. Good B&W photography is a different animal than color, and requires a specific visualization of the subject in just terms of light and dark WITHOUT color. When there was little color photography done, when I got into it over 50 years ago some photographers would carry with them a deep blue glass filter they would use to look at the subject to see it in monochrome tones of light and dark. The contrast that is created by different color in a subject can disappear in the monochrome of B&W. For instance an scene of greens contrasted with red may be striking in color but of the "light" value of the green and red is very close, in B&W the scene may look very flat and uninteresting. By photographing in black and white you could enhance the subject contrast by using a color filter, like a red, which would render the greens darker and the reds lighter in the B&W photo result.

All I am suggesting here is to modify your expectations by what is possible, and possible learn to enhance the results by recognizing how color contrast can be translated to B&W contrast, or vice versa of course. It is a matter of using your visual perception more critically. possibly with the aid of a monochrome (blue) filter and recognize in your vision of the photograph what it looks without color, so with that visualization you can plan how it can be converted most successfully to a B&W photo that works.

It should take only minutes to convert a color photo to b&w. I would suggest to always start with a color image, not a b&w image that your camera may (or may not) give you. The simplest, but not necessarily the best way is to use Image/Adjustments/Desaturate and then use Levels and Curves to adjust black point, white point, tonality (darker or lighter) and - by applying an S-curve in Curves - adjust contrast. A better method is to use Image/Adjust/Channel Mixer and check the Monochrome box. By varying the percentages for the Red, Green and Blue Source Channels you can give different "weights" to each color, dramatically influencing the way the monochrome image will look. Use Levels and Curves as explained for the Desaturate method.
Try out both; these are fairly simple methods to use and once familiar with them you will be able to apply them in minutes to get great looking b&w images.

Go to Popphoto.com - Popular Photography's website.

There is a tutorial there about converting to B&W that you may find helpful.

Thanks Erik. I appreciate it.