So when modeling, sometimes I add so many random edge loops to tighten up subdivision that the topology just ends up looking ugly. These random edge loops come from creating detail (such as a fin on a dolphin or a wing on a plane). What is the recommended way to deal with things like this? Is it better to simply add more edge loops/geometry to fit this extra detail in? Or is it better to create a brand new object/mesh/shape and append that to the current geometry?
This is really a personal preference thing. I personally dislike appending objects because it often ruins the loops of the mesh. The ugliness of the mesh is fixable by point manipulation. you can drag the points to move them into places that look better. another thing that might help with that is the "adjust cage to modifier result" Basically it makes the lines appear as if they are actually on the subdivided mesh, making point manipulation a lot easier to visualize. I used this when making a face model, it saved me a ton of time.