curious about valve lash setting/check

hello all, been reading, and reading, but haven't found an answer to my curiosity. my apologizes if this has been answered: when setting valve lash, I have read many tricks of the trade. what I am wondering is, should the rocker have 'approximately' the same distance from the valve stem when you work the tappet with the hex key after setting? or will the oil pressure make the difference when the engine runs? while on the subject, should you feel resistance when applying the 1/4, 1/2 (or whatever your preference may be) turn of 'load' after you feel resistance on the push rod? or should it turn freely? some say resistance, some say the push rod to stop spinning before you start to put load on the lifter, have even read putting oil on your fingers to tell when you have the 'enough' resistance to start applying the recommended load turn, then tighten the nut. but I haven't read anywhere if there is a 'check' per gap when rocking. I understand the hex key and nut will have different gaps (hence the adjustment). thank you all for your knowledge, I spend waaaaay too much time on the computer when I start reading on this site, and love every minute of it! thanks all, Jack