Make Morse a part of your daily life. When you walk down the street translate signs into morse, and sound them under your breath. At home, translate newspaper text into morse the same way. Always keep yourself stretched out in your receiving practice. You now have good buffer for the test.
Most people find it easier to print rather than write at first.
Avoid anticipating what is coming next. Many mistakes are made during the test by those who wrongly anticipate the following character or word. Learn sending only after the correct sound of the characters is embedded in your mind. Use a straight key but open up the contacts to a reasonable gap for a start with the key secure and on the edge of the table. Arm at right angles, elbow level with the key.