Interpreting your own handwriting as well as your friends is easy but you should do it for fun only. There are many factors that affect the style of writing. If your friend is on drugs while writing, the result would be influenced by the drugs. When a person has a stroke or other disease, the handwriting will be affected as well.
Large: You are outgoing and extroverted. It is said when you use large sized letters,
you like to be the centre of attention.
Tiny: You are focused and can concentrate easily. You tend to be introspective and shy.
In between: You are well-adjusted and adaptable.
Rounded: A person likes to please others. This person does not like being confronted.
Points: You are curious and like to learn new things. This person is ambitious.
Open: You do things opposite that is different to what your heart says.
Write it in Print: You are adaptable.
Full: You are relaxed and can easily express yourself.
Closed: You tend to be doubtful.
Full: Open minded and tends to enjoy new experiences in life.
To the left: You like to work alone. You are quiet. You think first before acting.
No slant: You tend to be logical, practical and reliable. But reserved and constrained.
Strokes: A high pressure in your writing means you have high emotional energy. Most
people that are successful have this type of enthusiasm and energy.
Connection: A person that writes connected letters is said to be logical and judges things
from personal experience.
Not connected: This person is imaginative. This person judges things according to instinct.
Wide: 'Give me breathing space'.
Narrow: Spaces between words means a person wishes to be with others
Wide-spaced lines: Show a wish to stand back and take a long view.Closely spaced lines: Indicates sensitivity.
Do not judge your friend's personality based on handwriting alone.