Prevention of the circumstances which could arise to cause a forced approach is important, but, like stall and spin recovery, ultimately the skill must be there to land a plane without power. This thread presupposes that you're up, you're going down, and you must get it right. The reason for this undesirable situation is worthy of many planning and prevention discussions - but right now, you're gliding....
There comes a point when you can't give power restoration your priority attention, you have to plan to get on the ground safely. For most pilots, that task could take all of the attention.
Selection of a suitable field is an important skill. If you can't make it to the field you started toward, at least you waste good gliding opportunity, if not fail completely. If you're right on top of the only practical place, you're going to have to get to an approach end before you can land on it, and that will involve some altitude costly turns.
And then there's just awareness of your choices to begin with. I was once mentoring a new pilot in his Tomahawk. I selected the perfect field, a nice grass runway, on his side, pulled the power, announcing "forced approach". He chose and set up for a pretty, but very small sod farm. I told him this would be a full stop landing forced approach. He told me that we would have a heck of a time taking off from his selected landing site. I hmmm'd a little to use up a bit of his gliding time, and then told him that we'd have no problem taking off from that nice runway over there. He completely re-setup his approach, and we made it fine. He did not look around enough, before committing, and I had left him lots of time. Tunnel vision.