Girls how do you feel about a guy who notices the little things. I tend to notice all the little details about what girls wear or do. If you change your earrings, your nail color, which shoes you like to wear, your favorite color, things like that.
For the most part, it's extremely, extremely sweet. I notice the little things about a guy, so it's nice when some actually appreciates you enough to notice the small things, and remember the small facts. It shows you were more interested in her than in yourself.
I've only had one bad experience with this: if you rattle off my history in the hopes of trying to impress me (versus being coy/subtle about it), it's a bit strange. I had a guy who I barely knew ask me to be his girlfriend. I then told him we needed to get to know each other better, and he said, "what are you talking about?! I know you!" and began recounting a laundry-list of my favorites/family history/all that stuff (your favorite color is green, you have two brothers, you hate football, your dog's name is...you get it). Things like that don't show that a guy knows who you are as a person. So as long as you don't brag to her and claim to know her based upon these things, you're golden.
It's a good thing, because girl's hope that guys DO notice little things, and try hard to make them notice. But be careful and not turn into a stalker by learning their address and stuff. Girl's tend to sometimes notice little things with what guy's say and do aswell.