A lot about graphology I found to be common sense if you think about it. The way you write reflects who you are. If you don't give a damn about your handwriting and write very messily, then it can be an indicator of many things. It can say that you're a messy person by nature who doesn't give a damn about much. Or it can simply mean that you are a "doer" type person who has a busy schedule and gets things done quickly.
But I specifically remember that if you do correct punctuation, grammer, spelling etc... then you tend to be very prim and neat in your life as well - paying attention to detail, and doing everything to the best you can do it.
Also, I remember that if you have "perfect" handwriting, than it can show you as a bland and colorless person. You were shown how to write, and you never deviated from it and gave it personality.
People with extravagent handwriting - very large, with lots of bold strokes - you are the same in life. You are probably a business exec who dresses very well to make a statement. Everything about you is persona and flair.
Keep in mind that mood changes also affects your handwriting.