First of all, I've come to realize that the "academic" method of collecting, pressing and mounting botanical "specimens" is quite technical, yet fascinating. To describe it briefly, the collecting and pressing aspects are based on rigid, botanical standards; however, mounting the specimens is a combination of technical guidelines and artistic "license." I have attached a link below that describes the proper technique for preserving botanical specimens for museum databases.
On the other hand, the techniques Olivia and I employ are very easy. When Olivia and I go out specifically to collect leaves, we bring the press and blotting paper. We carefully choose 2 or 3 perfect leaves from a given tree, place them between the blotting paper sheets then clamp them in the press. If we don't have the press with us, we will place leaves between the pages of a phone book (the only good use for a phone book these days) then transfer the leaves to the press as soon as possible.
We empty the press after about one week. But, we typically don't mount the leaves at this point. We store our leaves between the pages of large, hard-covered books. Don't worry because at this stage the dried, flattened leaves will not damage your books.
When we're ready, we mount the leaves. We simply place a few dabs of white (Elmer's) or yellow glue on the back of the leaf, then flip it over on your paper. Then, use your fingers to clamp and smooth out your leaf.
We then like to write a note or two on the front or the back of the paper. These notes may include the common name, scientific name, shape description, date, location, or something personal; like, "My First Shantung Maple Leaf Found in Fort Collins!"
We then place the mounted leaf in an acrylic frame and stick it on the fridge or any metal surface. Also, Olivia frequently opts to turn her mounted leaves into birthday or friendship cards.Feel free to contact me if you have any questions because I love talking leaves (and baseball.) You may also contact Olivia. She too loves talking leaves (and cats.)
"Plant Collecting & Mounting Guidelines" by Carnegie Museum of Natural History
Also, I recently purchased a museum quality, botanical specimen from Sarah Presogna in Philadelphia. I highly recommend her work and suggest you visit her site: https://www.etsy.com/shop/Ecobota