Here are some prompts you can use when journaling in nature. Please note that you do not have to buy a journal, you can make your own like the example below.
Draw or sketch one thing
Collect one thing and tape it to a page
Do a tree rubbing
Place flowers or leaves under paper and then color over them with crayon like a stencil
Write down any animals you see or here
Copy the phases of the moon
Use stamps to make a picture.
Draw the shapes you see in the clouds
Write down
one thing you see
one thing you here
one thing you smell
Here you will draw with a time limit.