Shampoo your hair dry them and then put some conditioner on them. Do not rinse the conditioner. Place a mirror in front and on your back side so that you can see both sides of your head during cutting. Now comb your hair and then gather your hair in such a way that they cover your face from all sides.
Start cutting your hairs around the face and trim the hair fringes holding them in two fingers for a leveled cutting. Once you are done with fringes, now starting from there proceed towards front side of your ear, repeat this for other ear.
Once you are done with the front portion of your ear. Start trimming from back side of one of your ear until back viewing angle becomes hard. Repeat the same step on the back side of your ear.
Now face the front mirror so that you can see back side of your head. Now start trimming back side of your head taking small portion of hair every time. Take extra care while cutting your hair when facing the mirror. Match both back sides of your head and then connect them.
Now pull out small portion of hair from all over the head to see if they are even or not, if they do not seem, trim them with the help of your two fingers and scissors.