I always twist stranded wire as long as I don't use ferrules. Never twist solid wire though, just makes it harder to get it into the terminal. Our choc blocks are usually that tight you won't even get the wires in if you twisted them before.
If I insert one single wire into a big terminal tunnel I do bend it back, otherwise I don't. Again, using ferrules you can't do that anyway, and in theory you're required to use them. For that reason i think it's much quicker to work with solid wires inside walls.
