The first "nature journals" I believe I ever saw were made by Andie Thrams, in the context of book art. Thrams seems to live outdoors: she has led expeditions in the Sierras, Alaska, Hawaii, and elsewhere, and she stops to teach others how to document and share their experiences in the wild and back at home. Her own works are gorgeous, richly colored, layered watercolors that her website notes are inspired by "illuminated manuscripts." I find them evocative and full of feeling. Like many other instructors, she has had to move her teaching online. (There is a quote from Thrams in Making Handmade Books, page 120.)
The closest I've come to nature journaling is my camping notebook, but it is nowhere near as detailed or lush as Andie's work, or as scientifically accurate and realistic as the work of John Muir Laws, who has written several books on drawing from nature. He, too, teaches online, with some sample videos available. I followed one to see his teaching methods and gleaned some new tips. With a strong background in illustration, Laws presents a system for drawing from nature. I found his work from a previous auction at Golden Gate Audubon Society in which the novelist (and painter) Amy Tan had put some of her bird paintings (as cards) up for purchase. Her little birds had a very charming and playful look to them, and I saw she had studied with Laws, which sparked my interest.
Drawing from nature, or drawing from photographs of nature, requires attention to details, those small closeup things again. The Laws Guide to Nature Drawing and Journaling, (Amazon link), 2016, is quite a comprehensive book. At first glance, I was completely overwhelmed, but when I started analyzing it in preparation for this post, I understood, at least for myself, how to approach it, and how others might approach it as well.
What's inside? This is a book about seeing deeply, learning about a subject and how it changes or can change and how you can capture it. It helps to go in with a question: what do you want to learn first? If you want to go straight to drawing you could turn to any of 22 "how-to-draw" sections (the iris might be the exception, because it uses quite a range of tools). I suspect jumping in like this is not recommended by the author, though, because the table of contents does not list page numbers for the step by steps, only for the chapters in which they fall. Additionally, the book introduces general terms of blocking in, line work, value, color, detail, depth, and composition that may be helpful to understand before taking up a pencil, and there are examples of each as well.
The beginning sections also talk about how to view the natural world, how to ask questions, to evoke curiosity, get inspired, take notes. It is quite a bit of reading, which is helpful, particularly if you teach. I was interested in the sketch for "What Does 100 Look Like?" because it is useful for birders in estimating how many in a flock.
He writes about traditional nature journals and scientific notebooks, and how a journal's page can include: maps, diagrams, photos, sketches, lists, counts/estimates, poems, quotes and feelings, and he presents samples pages that show how you might organize the information.
If you want to choose materials or enjoy looking at art supplies (yes, I do), there is an in-depth section with photographs of all the tools and materials you might like and suggested "field kits" for each: watercolor pencil, watercolor, colored pencil, pen and ink, mixed-media, and "Your Kit."
If you want basic art concepts, such as composition and color, there are chapters for those. You can draw on toned paper, you can make rubbings and stamps and tracings, so many options. Later on, he explains that waves are not symmetrical and shows a more natural composition. He demonstrates how to make the edges pop (white gel pen is good for this), and how to make transparent wings. As I said, this book is packed with information!
One thing a beginner will have to do is to make the leap in his instructions from the basic "blocking-in" with erasable non-photo blue pencil to the outline of the bug or bird or leaf, which he draws in its entirety before he moves on. No one-line-at-a-time for this step.
In summary: The techniques of how to draw and paint are interwoven with tips and tricks, materials, and ways of seeing. It might be easier for the beginner to start with one of the "step-by-step" projects and add to one's knowledge after completing a few, since questions are bound to arise as one actually begins to draw. From materials to color to shading to composition to philosophies of looking at and making art to scientific notebooks, this book is solidly the only book you would need if you are interested in documenting the nature around you. It is a serious guidebook for eliciting curiosity and joy in looking at nature and accuracy in painting and drawing. It helps to pick one thing to work on at a time. And perhaps take it outside and practice it for a while to make it your own.
At the same time I checked this book from the library I also checked out a friend's recommendation: The Bird Way: A New Look at How Birds Talk, Work, Play, Parent, and Think (Amazon link), 2020, by Jennifer Ackerman, which features various quirks of bird nature and how we relate to them, primarily looking at birds in the Southern Hemisphere (mostly Australia and New Zealand) like Kea parrots (hilarious! check out the videos online). At the end, Ackerman points out that the word "auspicious" derives from the observation and divination of movements of birds, an inspiring thought. Maybe today will be a lucky bird day.