There are different categories of sweet, cheesy sweet and unusual sweet. Both have their good sides. Try to get a good mix in.
Cheesy sweet (easy, by the book stuff. Should be said at least once every few days, while cuddling and in privacy):
"You are beautiful" - Girls like being told their hot, good looking and sexy, but when a guy says you're beautiful, thats what really gets a girl's heart to melt.
"I'll always be there for you" - Sensitive guys win. Always.
"You make everyone pale in comparison", "There is no girl like you" - Females like to know that they are better than other females and it helps to know that your guy thinks that about you.
Unusual sweet (more original lines. Makes your girl feel special. Stuff along these lines should be said at least once a day, doesn't matter when or where... preferably comined with a kiss and a hug though):
"You're so good to me it makes my heart hurt. Although it could just be the cholesterol." - Girls love to be appreciated. And its funny cute. Girls like it when you make them laugh.
"Your sweetness is going to make me diabetic one day." - This brings the awwwwws.
"You're so yummy i'm going to eat you up!" - This is cheesy and unsual-ish all at the same time.
The list isn't too long, but take some poetic liscense with this stuff. Stuff along these lines will always put a smile on a girls face. And compliments, girls LOVE compliments! Tell her she lost weight, she looks extra gorgeus today, she has pretty eyes, she dresses well, etc.
This stuff is easy! Learn to say the right things, and you'll never have a problem scoring a date (or keeping one!)
