Here are some more ideas to get you started.
Engage the fives senses (whenever possible)
Make leaf prints ( paint the leaf and press the print into the journal)
Observe the movement of living things surrounding you
Count the birds/squirrels/insects etc.
Measure as much of the phenomena as the students can using non standard and standard units of measurement.
Here is a downloadable lesson from John (Jack) Muir Laws and Emilie Lygren book: How to Teach Nature Journaling. All resources shared with permission. "I Notice..., I Wonder...?, It Reminds me of..."
GIVING FEEDBACK here is a fantastic resource from Jack and Emilie
NOTE: You are encourage to spend time in the outdoors Nature Journaling. However, you can also bring nature inside, look out your wonder window, have a refrigerator Safari or even observe a house plant or pet.
1. Tree Pose
2. Bat Pose
3. Fox Pose
4. Coyote Pose
5. Eagle Pose
6. Turtle Pose
7. Butterfly Pose
8. Log Pose