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)
Make leaf rubbings
Trace the items they are looking at
Add leaves into the journal using tape
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.
Accessing a safe water source
Finding food that is safe to eat
Warmth or shelter
Shelter frame - put a tarp or other piece of material to hang over the line and create an A-frame shelter to protect you from the elements
Tying down loads - canoes or anything on top of a vehicle or trailer
Creating a clothesline or line for hanging heavy or wet objects