PabloS right about posting an example, and about the focal length... absolutely right for portraits, but you can use a smaller length if you're further away from the subject. Absent an example picture, I would speculate that if you have good textures, lighting may be the missing ingredient to your mix. Assuming you're using P4, search the FreeStuff here for SnowSultan's Illustrender and Pinup sets, also the global set from PheonixRising (yes, spelled like that), and Shademaster's Renderupgrade set (a realistic outdoor light set).