Factors to consider: what do you want to do (game drives, cultural experiences, other); small group tours or private; luxury, very nice or budget; any particular countries. If the tour includes travel to other countries and areas remote from where you start, be sure you don't end up with any 8 hour bus rides. Look for intratour air travel for long distances.
You can do long distance plans with operators in Africa or use your travel agent, but one way to save the trouble of putting together all the elements of a trip would be to start with some tour operators based in the USofA, like Tauck, Odysseys Unlimited or Abercrombie and Kent. Some even include the airfare.
They offer small group tours to different locations all over Africa, all times of the year and all stay at very nice hotels. We liked the idea of meeting other people and had the good fortune to be with two great groups. Group size for the two we did were 14 and 10 and most use the same hotels but check them out online. With Odysseys Unlimited we stayed on the rim of the Ngorongoro Crater in the same hotel chain Tauck uses, for example, Serena Lodge, and that was true for the other areas of the Serengeti. Not sure about A&K. If you want posh they're a good place to start, but our focus was on game drives, not 1000 thread count sheets. And if you want to do a hot air balloon ride and it's not included you can easily add it.
The first thing we did was look for tours that offered lots of game drives. The tours typically have one or two per day, with one early in the AM and one in the afternoon, with a night drive sometimes offered. Parts of days may be reserved for travel if you're going to different parks/countries and other parts are reserved for sightseeing other than game drives, hot air ballon rides and cultural events, depending on where you are. We found the guides would modify the itinerary slightly if we all wanted an additional game drive for example.
After reviewing tour operators' offerings we made our choice based on which stayed in the nicer lodges/tented camps and offered the game drives we had as our top priority. If we were on safari for 10-14 days we wanted 15-20 game drives.
We liked late July/August because the weather is dry and cool (need blankets on your lap on the early AM drives) and the animals are active. First trip was two nights in Johannesburg, three in Botswana (Chobe), three in Zimbabwe (Victoria Falls area), three in Zambia (luxury tented lodges on the Zambesi River) and three/four days in Cape Town at the One&Only Cape Town with its great view of
Table Top Mountain and other sights as shown below: Fine woman not included.
The second trip was Tanzania and we focused on seeing the Great Migration so we chose late July..........unfortunately there were drought conditions which lead to the Migration happening a couple weeks earlier that year.
We did have the good fortune to see a fresh lion kill of a water buffalo in the late afternoon one day (five adults and one young male lion) and the aftermath of the kill the next morning. The lions were still around, about 100 feet away in the tall grass, but they were so stuffed they were just laying around. However, while there were only the lions the afternoon of the kill, the next morning there were about a dozen vultures and 60 to 80 hyenas arrayed around the kill but about 25 to 200 feet away. The birds were bold and tugging at the little flesh left on the ribcage and legs, while the hyenas were warily approaching with their heads moving like bobblehead dolls as they kept their eyes on the nearby lions. One lion heard the crack of a rib as one of the hyenas snapped it off and got up and strolled over to the carcass. As it did so, the birds scattered and the hyenas bolted away. You'd think that many hyenas (brutes with massive jaws and bodies) cold do a number on a lion but there's a reason the lion is king of the jungle/serengeti.
