I don't have any tricks.. but would love to hear if others do.
I either use the number specified in the pattern-- if I think it looks right

or more frequently do my own setout of stitches and I use a crochet hook to precicely 'dig in' and grab the yarn thread.
Firstly I pick all the stitches up pretty loosely, then go along and tighten each one up on the (circular) needle evenly before I do that first row. Not to make them too firm but just to make them all the same-- otherwise the line will look wobbly.
The other thing I consider is a first row of all knit (or purl) before launching into rib or moss... because I think the eye can be drawn to that threshhold between neckband and pullover and I want a smooth line. Sometimes this doesn't seem right-- (wouldn't want the neckband to 'float' around the top.. )
So in the end its a bit of a judgement call really..
cheers
mm