Remember the order of flats in a key signature.The order of flats are B E A D G C F. Use a memory device such as "Battle Ends And Down Goes Charles's Father" or make up your own creative saying. Key signatures are used to help you know what major or minor key that you play or sing in.
Remember the order of sharps in a key signature. The order of sharps are F C G D A E B. Use "Fred Can Go Diving At Ends Beach" to remember the order or make up a mnemonic device of your own.
Memorize the circle of fifths. The circle of fifths is a complete circle diagram to remember the number of sharps or flats in major and minor keys and the number of sharps or flats in a key signature.
Remember the major scale formula. The major scale formula is WWHWWWH, where "W" stands for whole step between two notes and "H" stands for half step between two notes. If you write a major scale for the key of G major that has one sharp, write the first note G then A on the staff in ascending order. G and A is a whole step between each other. Next is B. A and B is a whole step. When you add C to your scale on the staff, you just made a half step between B and C.
Add a grand staff to write major scales on staff paper. A grand staff is two staffs that are joined by a brace to play notes simultaneously by you. You use this to write music to play scales on the piano. The treble clef is the top staff and the bass clef is the bottom staff. If you want to play major scales only for one staff, do not join two staffs together, but choose the clef you want to write your sheet music.
Write out your key signatures for sheet music. Key signatures are placed after the clef. Write key signatures in the correct order of flats and sharps based on the clef that you play or sing in. For treble clef notes, you write accidentals (sharps and flats) higher than bass clef notes. For example, for D major scale that has two sharps, you will make a sharp on the first line of the treble clef staff. The first line is F on the staff for treble clef. If you remember the order of sharps for key signatures, F is the first sharp. Then you will write a sharp for C on the third space on the treble clef staff.
Add your time signature. Time signatures tell you how many beats per measure and what note gets the beat.
Write out your scales. Remember, write out scales according to the major key you are in. Write the first major key note in the scale. If you write a scale for B major, the first note is B. Write major scale ascending and descending for sheet music. For each measure, write two groups of four connected eight notes.
Add a repeat sign at the end of the last measure if you want your major scales played again for your sheet music.