For the purpose of this question lets say we need to append() 1000 objects to the body element.
You could go about it like this:
If you're going for raw performance then I would suggest pure JS, though some would argue that your development performance is more important than your site's/program performance. Check this link for benchmarks and a showcase of different DOM insertion techniques.
edit:
As a curiosity, documentFragment proves to be one of the slowest methods.