Apart from clothing, essential items and vaccination certificates
Secondly, the essentials - Personal toiletries - Anti-Malaria tablets
A camera (and / or binoculars) are a must
Camera film and batteries can generally be obtained in any major city or town. But of course the further away you get from civilization, the likelihood of availability decreases - like everything else. So please be sure to have sufficient supplies for your needs prior to embarking on a long trip.
Towel, torch and sleeping bag for camping safaris (sleeping bags can be hired from most safari operators). Also bring any reading or writing material you might need. You will have moments when you want to do something other than nothing at all.
Generally, casual comfortable clothing is suitable throughout the year but you may want to include items such as:
Light cotton tops and cotton trousers / shorts in summer
Long-sleeved blouses / shirts for game drives or safaris (even in summer, they will protect you from the sun and from mosquitoes)
Safari trousers for evenings and cooler days
Shorts or a light skirt
Jeans or safari trousers for evenings and cooler days
Khaki, brown, and beige colours - for game hikes and safaris.
White is not a suitable colour for most game viewing or hiking safaris. Firstly it increases your visibility quotient to the animals you are wanting to get a closer look at and secondly,it will get dirty very quickly.
Fleece or sweater and a windbreaker for game drives, because it is highly possible that you may go out on a hot day, but be faced with a chill evening on your return. Some areas have a steep temperature gradient. ie: Hot days and very cool nights.
Sunblock, sunglasses, hat, insect repellent, moisturiser, lip salve - these are essentials. The African sun is harsh most of the year.
Comfortable walking shoes or sturdy hiking boots. Sneakers and trainer type footwear is not suitable for game or safari hikes, especially white footwear.
Layers are most practical for the fluctuating day / night temperatures of Africa. Dull and / or neutral colours are more suitable for safari.
Cotton clothing is recommended for summer. It is best to pack hardy, durable clothing.