What's it called to be cautious about something you do?

Is there a term in English for where you want to describe the discreet or cautious approach you take, when you want to make sure you're not risking or jeopardizing anything in doing a routine job?

How would a native complete these sentences?

The _______ is to take two more spare tyres with you when you go off-road.

OR

You have to bring a sleeping bag, in case it gets cold in the forest over night; that is called _______, my friend :)

I think the word you are looking for is precaution.

The best precaution is to take two more spare tyres with you...

That is precaution, my friend.

I think the word you are looking for is prudent

Defined in the American Heritage dictionary¹ as:

1. Careful or wise in handling practical matters; exercising good judgment or common sense: a prudent manager of money.
2. Characterized by or resulting from care or wisdom in practical matters or in planning for the future: a prudent investment.

Your sentences would read:

The prudent approach is to take two more spare tires with you when you go off-road.

You have to bring a sleeping bag, in case it gets cold in the forest over night. That is called being prudent, my friend:)

^{1_{American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.}}