I tipped the cook staff and tracker $150 ea., again on the recommendation of the safaris company.
I also brought a couple of new knives and caps for my PH and tracker. Keep in mind that the days of missionaries and tents are over in Africa. It's all about money in today's hunting world and that's what they prefer. Hope this helps.
You may also want to consider if you give the whole tip to the Outfitter and let them distribute to the PH, Tracker, Cook and Staff or give it to each of them directly. Pros and cons to both approaches. I know one Outfitter, who I trusted completely, that he preferred getting the tip and distributing it because if the staff got it early they might use it to get drunk and not show up for work. LOL, true story. Some camps have a way they like to distribute the tips between the different roles so it keeps peace in the camp but in the end it is your Tip, not the Outfitters and PHs so you tip what you want and how you want.
Also, a gift or token like a knife, range finder etc is nice touch to do but you have to also realize you might be giving the something they already have or don't need. So is a little presumptios. I always take gifts like that as above and beyond. One of my guides had dropped his range finder into water a few hunts before I got there and I had taken two with me so during the hunt I gave him one of mine to use and I used the other. At the end of the hunt I told him to keep it and he was thrilled because there was a need. I'm not sure that would have been such a great deal for him if he already had a working range finder.
Again, just my experience/opinion and it varies but hope this helps you.