If you're doing insects I wouldn't bother with a reversed lens + tubes, its going to be pretty slow to work like that and the working distance won't be enough. 90-105mm is a good working distance I would say. Jumping straight to the Nikkor 105mm 2.8 VR isn't a particularly good idea, that's basically the most expensive…
I was more talking about specific styles/types, so like: Sports? Weddings? Portraits? Landscapes? Cityscapes? Interiors? Low light bars/clubs with friends? Low light exterior/nightscapes? Pets/birds? Vacation snapshots in daylight? Long exposures, for waterfalls etc? The specific sort of things you want to do will tend to…