Islamic will should deal with:
1. All the liabilities on you whether for people like loans on you, rights of others on you, Amanaat (trusted properties or money for people with you.
2. It should mention religious duties remaining on you like Qadha prayers, Fasting, Hajj, Nathr (Oaths and commitments.
3. It should also mention your rights which you want to take back from others. It will be part of what your inheritors will inherit from you.
4. It is highly recommended to keep one third of what you leave to be spent for your benefit like religious obligations and charity.
5. It can also include what you want regarding your children and who should be their guardian and advice you give them for their future.
6. It can also include your wish regarding details and place of burial and charity to be given immediately after your passing away.
7. The shares of your family members who will inherit you must be according to Islamic Shariah with out any change, unless the change is withing the one third only i.e. If you want to give your wife or your son or daughter more than the designated share in Shariah, the extra amount must not be more than the one third. Obviously , you will be then depriving ourself from the amount of one third which is supposed to be spent for your reward after your demise.