How can I check for myself if the ball joints in my Ford F150 need replacing?

Front wheels right? Twin i-beam suspension? My 71 wears on the inside
it appears to be a trait of the twin i-beam. Aside of getting the front end aligned
my solution has been to buy cheaper front tires and put more $ into the rear tires – I have wider tires in back.

I did replace the ball joints- it made no difference.

I’m not concernrd with tire wear, I need to know how to look at my ball joints and be able to recongnize if they are bad or not, because if they are it can and will leed to other front end problems. I also don’t care about alignment, all that would follow the ball joint issue.