Smooth lines in PS CS4 v. 11.0

I want to do nice smooth inklines when drawing in ps but I got a really old version of ps (CS4 Extended version 11.0) and I can't find any help on google or youtube. In my version of the program I can only find a check box for "Smoothing" in the brush options window. When I mark/lock it nothing happens. I want to be able to have more effect because now my ink lines are really ugly and wobbly. I'm not giving up hope that this is impossible in my PS version because I remember seeing other artists making smooth lines when this version was new. Can someone help me? Maybe it hasn't the same name as in the newer versions ("smoothing")? I've tried all the options now but I can't find anything that makes these smooth lines 😥