英语外形作文的写作步骤如下：

确定主题

首先确定你要描写的人物是谁，例如朋友、家人、老师等。

选择明显的特征

选择几个显著的外貌特征进行描述，如脸型、眼睛、鼻子、嘴巴、头发、身材等。

使用形容词和描述性语言

使用恰当的形容词和描述性语言来描绘这些特征。例如，可以使用“round”、“oval”、“high”、“small”、“big”、“curly”、“long”等词。

注意细节

描述时注意细节，这样可以使作文更加生动和具体。例如，可以描述眼睛的颜色、鼻子的形状、笑容的特点等。

组织句子

将描述这些特征的句子组织在一起，确保句子流畅且逻辑清晰。

添加个人感受

如果可能，可以添加一些个人感受或评价，使作文更具个性和吸引力。

示例1：描写自己

"My name is Tian Jiaxu. According to my mother, I have a round face with arched eyebrows, big eyes, a high nose bridge, and a small mouth. I thought I looked like this, so I washed my face in the morning and observed myself. However, my mother said I was not the same. My face is not very round, a bit like an egg oval, with eyebrows that are not curved but rather straight and some are upturned, and some are bent down. My eyes are still big, but the bridge of my nose is not at all. Anyway, I haven't seen it for a long time, and my mouth is big. I can plug in an orange."

示例2：描写朋友

"My friend Vivi is a lively and smart girl. She has long black hair and is the tallest in our class. She always wears a bright smile and has a charming personality. Her eyes are bright and her skin is fair. She is a very popular girl among our classmates."

示例3：描写母亲

"My mother is very beautiful. She has a round face with big eyes and long hair. She is a kind and caring person. Our classmates all like her very much. She is my favorite teacher."

示例4：描写英语老师

"Miss Tang is my English teacher. She is very pretty. She is tall and thin with curly, long hair. She is in her good manners, and you will feel that she is very amiable and noble if you meet her."

通过以上步骤和示例，你可以写出一篇生动、具体的英语外形作文。希望这些信息对你有所帮助!