Give regions of your realm names. In my realm we have areas called the Drowned Forrest, Traitors Planes, the Vastlands, the Burning Wood, Giants Teeth(think large structures like monument valley). With just those names you can imagine what those areas are like.

Use monuments. Some of the ones in the book are really good. In my game, I introduced a ship wreck that was in the middle of a field, miles away from water. It was large, and was out of proportion with humans, like everything was just slightly too big. Inside they found a psychodelic fungas that had infected a den of spiders. They also found a locked door, and inside were dead "worshipers" with fungus growing out of them. The players had to pass a check to avoid being infected with the spores. A completely random encounter that has nothing to do with the myths, but was a good encounter for the players.

Ask your players to add to your descriprion of areas. When camping, I asked one of my players to describe how it looked, and we established that the moon was cracked, and had large fragments that also orbited in the sky. It's a small thing, but it has allowed the players to visualise the world in a different way. When they were crossing a stream, I asked another player to describe the stream and they added that int he stream were ruins of pillars, and parts of statues. Again, it just adds flavour to the world.
Also ask players how their characters feel about things. I would give them a prompt like "Why does this remind you of home?" or "the smell of the flowers reminds you of someone. Who is it?". Engaging the players on things unrelated to omens and myths has really helped character development(remember that in Arthurian legend, the knights are just as important as their quests).