photographing tree bark

I'm getting ready to photograph some tree bark for a plant identification project. When I have done this in the past I have more often than not gotten less than ideal results. Identifying trees by bark requires being able to see the patterns in the park, which are not always apparent in my photos.

For this go-around, I am thinking I want to shoot in sunlight, with some, but not overwhelming fill flash. I'm wondering if I should always have the sun at a certain angle, maybe 45-degrees to my back? Or perhaps a broader range of lighting will work?

I'm thinking there are some lessons to be learned here from portrait photography... which I never do.

Any input would be appreciated.

I suggest that you should take photos under the sunlight in a specific range, do not get too close or stay too far from the tree bark if you want to see it clear. It's just my idea, I'm not a professional. If you want to consider more, you can also wait for other people

It seems to me that the best picture will come out if you cut down the trees since you can put it on the sun and because it will be convenient for you, but in order to cut it correctly you need to: cut it in comfortable working clothes. Sleeves, trouser-legs should tightly fit the body, all clothing should not have freely hanging ends, which can be caught. Protective goggles should be worn over the eyes, and special ear plugs on the ears will protect against noise. On the head you need to wear a helmet. The sole of the shoe should not be slippery. You still need to choose how you will perform these actions this link