Draw a treble clef sign by copying the image in the picture. When creating a treble clef, make sure that the curved line wraps around the G-line.
Write the melody out on the treble clef staff. A lead sheet only has one staff as opposed to a typical piano staff, which contains a treble and bass clef.
Insert chord symbols above the notes in the melody that fall on main beats. For instance, the first beat of each measure needs to have a new chord. You may add a second chord on the third beat if it fits the melody.
Identify the number of measures in the melody. In a standard four-bar melody, the third measure should have a chord starting on the fourth scale degree of the key. For instance, in C major the third measure should have the chord symbol "F" to indicate that an F major chord must be played.
Insert a chord that begins on the first scale degree in the first measure. The preferred chord to use when opening the lead sheet will be based on the first degree of the scale. In the key of C, that will be a C major chord.
Apply a chord to the second measure that fits the notes in the melody. If you are in the key of C, and the melody note is an F, you can use a D minor chord or an F major chord. Both of those chords have the note F in them and will work.
Add the final chord for the melody by coming back to the first scale degree. In the key of C, the first scale degree will be C major.