May your needles always be centred
Easy! I find if I turn a knob on the box all the way to the left then the a/c automatically gets centred on the LOC & GS as shown on the standard CDI display. It even shows a little red flag to let you know you're well within tolerances. Must be so because ATC stop complaining & go quiet...
Oh, the question. It's a non-precision procedure so I use 1 sec / kt / min on the guestimated HW/TW component, rounded to the nearest 5 or 10 seconds.