One of the most important things to understand is the power of imagery in marketing. It's not because images make things pretty. The brain uses images to orient to most things. Over 75% of the brain is devoted to visual imagery. That's how we work. People with a photographic memory even remember text as an image!
The most powerful thing you can do is to connect images to your marketing that help carry the message you want to get across and reinforce the meaning, especially in an emotional way. People remember images more than they remember words, but a great image can remind them of the 'word message' it stands for.