There are defeats more triumphant than victories.
~Michel de Montaigne
There are many things you just won't learn until you've gone and screwed up. This is why it's so important to experiment and determine what works well for you.
It's also prudent to remember that as time passes, what once worked well for you may no longer fit the bill. What better way to experiment than to make mistakes?
(1) Overtrain. Push yourself point the past of no return. Run too often, too far, and too fast to see what happens to you. Maybe nothing will happen and you'll have learned something, or more likely you'll understand what it's like to overtrain.
Notice your desire to get out and run is dampened. Feel your muscles in a constant state of flux. Experience the nagging injury that you never let heal. Your joints, bones, and limbs hurt. You keep getting sick.
If you push yourself too far, you'll begin to understand where your line is, and what it feels like as you cross it. With that knowledge you will be better prepared to respond to future tussles with that overtraining line.
(2) Push through the pain. When you feel a sharp pain, keep running, see if you can push through the pain. Maybe you'll be able to, or more likely you'll pull up limp with an injury.
If you've hurt yourself running before, you'll do everything in your power to stop that from happening again. Perspective on the pain will help guide your actions.
Understanding your pain, specifically what type of pain your experiencing is crucial to running. Knowing when to pack it in and when to push through will keep you healthier and more injury free.
(3) Give up. You're 2/3 of the way through a tempo run and it hurts, you want to stop.
Quit, stop running, give up and walk.
See what happens to your mind when you give up. Do you feel guilty for your actions? Do you feel like you've cheated yourself out of a quality experience?
How does your body feel after you've stopped? Do you think you could have kept going or were you really at the point where you would have simply thrown up on yourself?
Perspective on giving in will make you stronger when the feeling arises again. You'll remember what it's like to give up and fight it.
(4) Use what works for others. You're reading advice here, and most likely elsewhere on the web, in books, from elites, from your buddy, and perhaps many other places.
Everyone has a story about drills, workouts, food, race tactics, etc. which have brought them superb results. Copy them exactly and expect the same results -- after all they did it and it worked.
Get baffled when you don't get the same effect. Why is that? Why was someone else able to do something which had no effect for you? Was it because you're a different person than they are?
(5) Race over your head. Try to run a marathon on very little training. Or a half marathon.
Sure you've only ever run a 5k at a local race, but how much longer is a half marathon anyway? Just sign up for a race, do what you can, and get your butt on the starting line for the run.
You'll be surprised what your body is capable of.
If you can't convince yourself to go that crazy, then go out hard in a local 5k -- faster than you'd think sane and hang on. You'll most likely wish you went slower, but what if you finish? What if you learn you're capable of more than your expectations?
Go ahead and fail already.
Your fear of failure may be the biggest opponent you’ll face on your road to learning to run well. Don't be afraid to flame out, as long as you learn. You may just stumble on something which truly resonates with you.
Now is a great time to become more of an expert on you.