If you have a video camera you can record yourself riding and look for problems.

I've done that a few times as I've adjusted my bikes. Due to old back and neck injuries I can't handle drops (for now, though I'm working on flexibility and strength exercises to see if I can manage it again someday). Whenever I adjust the handlebar height and reach, saddle, etc., I record myself riding back and forth, toward and away from the camera, to look for problems, particularly with neck position -- I have to avoid craning my neck upward at all, due to permanent C2 damage.

And I ride with an action cam on my bike or helmet to record rides, mostly for documentation in case of an accident. Usually I delete the videos since nothing interesting happens. But a few months ago the handlebar mounted video camera was blocked by my handlebar bag. So I flipped the camera around toward me to record looking behind me, on a lark. I moved the camera around every few minutes just for a variety of recording angles.

Later when I reviewed the video I realized I was rocking in the saddle. Just recently I'd been experiencing some unusual hip and lower back pain (my chronic pain is upper back, neck and shoulders). I realized I'd set the seat post too high. Lowering the seat post just a smidge resolved the lower back and hip pain.

And I do a little stretching before, during and after rides. Usually I'll stop after 30 minutes to stretch a bit more, since it takes that long for me to warm up. Then again whenever I feel any twinges.

Personally I wouldn't use clipless or toe clips again, even though I used toe clips for years when I was younger. I don't doubt that they're more efficient, and I'm probably robbing myself of some advantages on tougher hill climbs and fast cadences on flats and downhills. But I prefer to move my feet around on larger platform pedals to suit myself. If I feel even a slight twinge in the knee I change my foot position slightly and it always helps.

When I was younger I had a fitting done with my hard soled cleated Detto Pietros and whatever was considered the fashionable bike fitting back then (French fit, I'm assuming). Possibly the worst mistake I made in bicycling. With my feet locked into one position, balls of the feet centered over the pedal axle, I began experiencing pain in my knees, arches, etc. And I was only in my 20s.

At age 59 I'm hoping to extend my joints as long as possible. Almost everyone in my family on both sides ended up with badly deteriorated knees, hips, etc., with osteo-arthritis and other ailments. It may be inevitable for me as well but I'm planning to delay it as long as possible. I take every twinge of pain seriously and do whatever's necessary to avoid it. Platform pedals give me the flexibility to move around and get comfortable over longer rides. I know I'm giving up some power, efficiency and speed, but I'm not racing anything but time so that's okay with me.