How to Use? When using neem oil dilute it with base oils like olive avocado sesame oil or jojoba oil. You can use between 10 to 20% neem oil in a blend. You can also add 4 to 5 of drops of lavender or ylang ylang essential oil to mask the smell as well as enhance its effects. Hereâs a blend that you can use: Take 1 tsp of neem oil 3 tbs of avocado oil and 4 to 5 drop of lavender oil. Mix all the ingredients well. Apply this on your scalp and hair and massage gently. Leave it for about an hour or so and wash as usual. You can also leave it overnight for more effectiveness.