So I've just finished creating my custom Tiefling Bard character and since I wanted her to be reasonably balanced, I based her character card on Lem's with just a few small adjustments.
But when I started to compare the stats and abilities of the other characters, I noticed the 'rule' of 24 (ish). Assume the following:
D4 = 1 point
D6 = 2 points
D8 = 3 points
D10 = 4 points
D12 = 5 points
(FYI Lem has 14 points worth of stats, everyone else has 15)
Each point of skill bonus = 0.5 point*
Hand size of X = X points
Each proficiency is 1 point
Most of the characters end up with 24 +/- ~1 point in total, with Harsk and Sajan being the notable exceptions at 26.5 points and 21 points respectively. Of course this doesn't take into account the 'value' of a character's innate powers and as systems go, I'm sure what Paizo used is far more complex. But if you want to create a balanced custom character this seems like a good way to go about it.