There's no such thing as "sloppy copy" in field notes. You're not supposed to rewrite them more legibly at some date in the distant future, when your hand has stopped cramping or when it's stopped raining. Field notes are supposed to be the very document you wrote when you were making your observations.
Some field notes have become really famous, like the ones Charles Darwin took on his voyage to the Galapagos Islands. If you spot a bigfoot, your notes will be invaluable, which means they will be worth so much money no one can put a price tag on them.
Also, take your time to make your hand-writing legible, or you might be very sad when you look at your notes a few weeks later and can't figure out what you were writing about. One expert tip: Write your notes before you collect your sample. That way, you aren't trying to juggle your notepad and a giant sack of bigfoot evidence.
FIVE THINGS TO INCLUDE IN EVERY ENTRY
Number each sample separately. Write the number in the notebook and on your plastic bag. Sharpie works best for this, but it will stain your clothes, so be careful and put the cap on tightly.
Describe the sample. What does it look like? What does it smell like? How big is it?
Identify where you found it. The more accurate you can be, the better. This is where a GPS device can be very handy.
Describe your surroundings. Are you by a river? Surrounded by trees? On a mountain slope? What kinds of plants are growing nearby? You can shoot a photo or video to accompany your description.
You should also date and time the location (with GPS coordinates if you have them), the weather, and the names of the people you're with.