Growing up, my mother often pressed leaves between the pages of books. In fact, it was rare if anyone opened a book in our house and a leaf did not fall out of it. Using the idea that I don't have to buy a flower press to press flowers and leaves, I recently made my own version with my daughter.
I started by cutting up 4 squares of equal size from a cardboard box. Next, I found old newspaper and folded it to the size of the cardboard. I used a couple layers so that the moisture of the plant would be absorbed by the newsprint. My daughter stretched 2 rubber bands over the squares to hold the newspaper in place. The rubber bands help make it more manageable for her especially if we are outside.
We placed the leaves and flowers on the newspaper and then put a another newspaper square on top of it.
After the leaves and flowers were put between the newspaper squares, we used two large rubber bands to hold it all together. We then placed a couple of heavy books on top.
After a week we carefully removed the plants. She glued the plants onto paper. I noticed she had even managed to press a dandelion. Although we didn't, I have read that bulky flowers can be carefully taken apart for pressing and after pressing can be put back together on paper (hmm, sounds like a good Montessori activity to me!)