Step 1: Don't bring a gun (this is generally a good idea anytime).
Step 2: Be absolutely sure of the identification of your edibles before you sink your teeth into them.
Ideally, you'll want to check your potential food source with multiple references including but not limited to
- plant/mushroom reference books or
- an expert or intelligent botanist or mycologist.
Step 3: Be sure to prepare the plant correctly, don't eat any poisonous parts, and eat it at the right time of the year.
If you were stuck in the ground, you wouldn't just let any ol' idiot with shorts and tall socks come and rip you out of the ground and bite into your skull. You would produce poisonous compounds to protect yourself. I know I would. Likewise, plants and fungi are extraordinary producers of secondary metabolites (compounds produced for certain ecological—often defensive–purposes).
Some plants or fungi are always deadly when eaten, but some of their associated chemicals may become deactivated through food prep such as boiling, frying, etc. We subscribe to the philosophy that preparation is just as important as identification. Follow the instructions that your books say–we'll do the same.
Some plants can be delicious, nutritious, and ambitious on one part, but deadly on another. That's what killed Chris McCandless. No bananas. Only eat the correct parts of the plant that you have identified beyond a shadow of a doubt and cooked perfectly according to legitimate instructions (we make no claim to the legitimacy of our instructions we write except that we lived long enough to make a post about our meal).
Step 4: Never eat any plant, animal, or fungus ever. Instead, subsist entirely on Swiss Cake Rolls.
Abstinence is the surest way to prevent pregnancy and STDs, but wouldn't it more fun to get educated and experiment? You would be totally safe to avoid any edible plants you find, but it is much more fulfilling to learn and try new foods from nature's bounty. It isn't risk-taking if you actually take the time to learn about the plant and read a few entries about it from several books—that's called learning. Plus, Swiss Cake Rolls will kill you anyway.
Step 5: Don't bring a gun (I don't think this can be stressed enough!)