Instructions on your pattern should include:
- The name of the pattern (for example, 'Bodice Block')
- The name of the pattern piece (for example, 'Front')
- Size (for example, 'Size 10')
- Cutting instructions (for example, 'Cut 1 on fold')
- Number of pattern pieces in the pattern (for example 'Piece 1 of 2')
It is also handy to write on the pattern whether it has seam allowance included or not (if you are not in the habit of marking the stitching line), as well as the date it was drafted (this helps if you are likely to make updates to the pattern, or if you have multiple copies of a similar pattern, with some small tweaks).
Some of these things seem quite obvious, but the clearer your markings are, the easier your pattern will be to use. You may want to use your pattern in a month, or even a year or two, and if the instructions are clear you won't waste any time trying to remember the details of your pattern.