I target reliable kickers on good, but not great offenses. I want to target a team that can move the ball between the 20's, but not necessarily have a great red zone % (because their drives often result in FGs rather than EPs). A strong defense is helpful to the so-so to good offense, but not necessarily crucial (teams that get in a lot of shootouts produce good kicker stats, too). A defense that is strong in one phase (rushing or receiving) but weak in the other is desirable for kicker stats, IMO - these are the teams that get in high-scoring affairs as opposing teams take advantage of the glaring weakness on D forcing high-scoring contests.
Also, I tend to avoid the ultra-cold-weather, outdoor venue kickers (Buffalo, Green Bay, Cleveland) as the kickers generally stink in December.
Also, as Mike Herman has demonstrated in his work, owning the Denver kicker is usually a ticket to a top-10 performance due to the 8 yearly games in conditions that are very suited to making long kicks (despite being near the Rockies, Denver is on the high plains and the winter weather isn't as severe as you would expect - not as severe as the three I cited above, anyway).
So, my progression is:
Denver Kicker (Prater this year)
Good kickers on decent but not outstanding offensive teams:
Nick Folk (NYJ) - for whatever reason, I ended up drafting him the most often in my staff leagues - probably because all of us are familiar with Mike Herman's Denver profile, and I never take the first kicker off the board
Joe Nedney (SF) - the offense hasn't been as good as I anticipated yet this year, but Nedney fits my parameters
Sea Bass (OAK) offense is improving, but the Raiders still ask Janikowski to kick a lot of long attempts
Stephen Gostkowski - poor RB stable leads to a decent number of kick attempts despite the powerful passing offense...
ETC.
My .02.