the best way to do it is have a some one move the wheel side to side for you while you look under the car. first look at the joint where the outer tie rod connects to the knuckle and look for alot of play, you will notice alot movement at the head of the joint if it is bad then keep looking down the rack if the inner is bad it will have alot play going in and out like it wants to pull out of the rack.
to check the lower ball joint take a long bar, lug wrench something to give you leverage, have same friend slide it under the tire and pull up and down on the tire while you look at the lower ball joint, if it is bad you will see play in it, the spindle part will move up and down over the ball joint. there is some play needed in the bearings but not too much, pull the wheel of and grab the disc and hub move it in and out and up and down that will tell you if you have alot of play. the bearings could be wearing and it will cause some play or if they where packed they might not been tightened has much as the other side. you might be able to pull the cotter and tighten them, i usually tighten them tight then back off 1/2 to 3/4 turn or until I can get then cotter in then recheck them but others can chime in on better methods if they have one. best of luck.