Diary writing is a form of composition. It includes a person's experiences and thoughts or feelings. It is a special way of expressing your memories through a handwritten format. 

There are some points which we should keep in mind while writing a diary. 

1. Date, day and year must be briefed.
2. Contents of the diary should be brief.
3. Signature should be affixed. 
4. Entries should look like real and natural. 
5. One's own reations to the situations should be written. 
6. There should be some significant turn of the events. 
7. Boring text should be avoided. 
8. Entries should not be monotonous. 
9. Living experiences should be mentioned.

 Here is an example of how to write a Diary Entry.

You are Ramesh. Today you faced an interview conducted by the principal for the post of the Head boy and got selected. You feel great pleasure. Write a diary entry to express your feelings. 

Hello Diary,
3 February, 2023
(Saturday, 8:45 P.M.)

Today was a day of big achievement in my life. I succeeded to achieve a position for which a lot of students dream to get. It was the post of a Head boy. When my class teacher showed my name in the list of selected by the school board, I was thrilled and overjoyed but nervousness could be clearly seen on my face. I was called for the interview and my name was shortlisted among others. But when my name appeared in the three names that were announced for the final interview by the principal, my joy knew no bonds. But this was not a bed of roses. A very short period was given to me to prepare for the interview. My capabale competitors were also strong claimers for the post. My momm told me not to lose my confidence level under any circumstances. It was an occasion of memorable pleasure when I was appointed as the Head boy at the ceremony. But with great position, have some responsibilities which I hope to fulfill with all my honesty and sincerity as well as hard work. 
Ramesh
The Head boy
J.I.S. Raghunathpur