The best option always will be to take a photograph from a professional photographer. Usually, you will find one in the shopping malls or the nearby market. These photographers are well aware of ICA requirements. Also, they have professional lighting available.
However now a days the phone cameras and apps are also capable of taking very good photographs.
We recommend that you download and use mobile apps that are specifically designed to take photographs for passport or identity card applications. These apps usually come with features that will help you take photographs in the required dimensions. Ensure to have some good lighting around and a plain background which you can then adjust as per ICA requirements to white colour.
You can also use the image editing software in your computer to resize the digital photograph.
Please note as per ICA your photograph must not be altered or enhanced in any way. This includes the modification of facial features and/or the usage of photo editing software. Please also note following specific directions about taking photo from ICA.