Excessive heat can cause damage and breaking. Make sure that you dont go over 450 degrees when styling your extensions . Flexi Rods are a great way to curl your hair without the excess heat, plus, they'll save you some time when it's time to get ready.
You Always want to cover your hair with a bonnet when sleeping! Place your hair in a bun, twist, or braid and then place the bonnet on your head. If you have a frontal install, you want to place a cotton scarf around your edges before the bonnet.
You want to shampoo your extensions at least once a week to remove any product build up that could be weighing them down. Comb extensions from ends to roots before shampooing. Never rub the hair together as that can cause damage and knotting. Also, Instead of using a heavy oil for styling, you should use a light mist shine.
If you have deep wave hair, only brush hair when it's wet and contain conditioner.