Never pass on a gift from the bush. Over the course of several safaris I've let good bushbuck, nyala, duikers, steenbok etc... walk because at the time I had no interest in shooting them. It is cheaper to take them when you see them than it is to go back.
Don't pass on opportunities for bonus type game. I've let caracal lynx, african wildcat, civet cat, bushpig and jackals walk because we were after "better" game.
Listen to the PH. Once when I was after zebra we saw a really big springbok. The PH kept telling me I should take it but I had already shot one and wanted the zebra. He finally asked if I would loan him my rifle and a bullet and he shot it. It went #4 or #5 in the Rowland Ward book!
