Modern aircraft tend to have quite reasonable cockpit visibility. But throughout history there were some that had literally no visibility directly forward.
The best known example is probably Ryan Spirit of St. Louis:
but there were others like Supermarine S6. Granted, they were all special purpose planes. But still, how did the pilot align with the intended runway and ensure the runway is clear? There was no ILS to help him, so it still had to be done visually. And how did he avoid obstacles and other aircraft?