If you push in on his face like so his nose will bend up in a natural place. This gives you a natural position on the face along the seam to place the eyes. While playing around with your eyes before, you may have found a place you liked better, stick with that then. This is a general guide line.
Go ahead and stick your round headed pins back in the places you've chosen. Now it's time to get out the heavy thread. I normally double the thread and stick the loop through the button hole. Pull the ends through the loop to secure the thread to the button.
Thread the two thread ends of one eye into the eye of a long needle. That sounded redundant! Push the needle through to the back of your teddies head towards the bottom around one of the seams. Your felt pad here will get in the way a bit so you'll have to poke around.
Pull the thread through.
Do the same thing again except bring your thread out next to but not in the same place as your last thread.
OK, I'm not gonna fool you here. I had mine knotted up and I wound up cutting it out again and starting over. Once you have your two threads through the back make a single knot, pull both strings gently in opposite directions, turn your bear over and look at him. You're going for a slight indent to the face, both eyes with even tension. Once you're there, and it might help at this point to have another person there to hold that tension, you need to knot it for good. It's not easy, this is probably the hardest part.
If you got the tension right, if you got the second knot done, turn him around again. Give his eyes a push in to relieve the tension on the buttons. Are they still right? If yes we'll proceed, if not start over, sorry.
OK, knot these threads up a couple more times. The picture above shows me taking two threads at a time, close to the knot, back into the bears head.
I've come out through the cheek. Again hold the tension on the thread and cut close to the fabric and the thread will disappear.
Sewed in eyes but a temporary nose. We need to work on that!