Seventy-eight percent (78%) of people relate better to concrete sensory data. Some of that group might be able to deal with abstraction. The other twenty-two percent (22%) deal more easily with abstraction. Probably three percent (3%) of the population really deals well with abstraction. So, be concrete. Youll have a larger audience and the whole of the audience will understand you better.
Now, if you are part of that 78% you might now be asking, What is this guy going on about when he talks about being concrete? Am I supposed to change my diet so my arteries harden? Use words that stimulate the senses. Talk about things that you can touch and feel or smell or taste or see. Instead of speaking of love, speak of a rose or heart. Instead of death, write of a reaper or skull. Now these examples happen to be clichés, which you should avoid, but they are metaphors that people understand as love and death. Come up with other real things to express the emotions.
Another habit that some poets fall into is getting into obscure references. T. S. Eliots book The Wasteland and Other Poems contains several bits and snippets in various languages. James Branch Cabell once wrote a book of poetry where he pretended to be several medieval and early renaissance poets from Provence and other regions with distinctive romance languages and dialects. These are instances of works that are directed at a limited audience. Eliots audience was a particular class of what we would now call the hyper-literate, people who had grown up in upper-middle to upper class circumstances and were educated in Latin, Greek, and the romance languages as well as English. It might be a reflection of the modern school systems that these old tongues are no longer considered important. Cabell was pulling a literary joke, and it was hardly the only one he executed, either. His audience was very narrow in focus.
Thomas Burnett Swann wrote several books that brought the old Greek legends to life. While knowing the legends in advance of reading one of his books, like Green Phoenix or Cry, Silver Bells, might have been helpful, it was unnecessary. He was bringing the legends back to life in fresh, modern English and with all of the elements of a tale well told. When he introduced a centaur or minotaur, there was a description. Michael Crichton did the same in translating Beowulf to modern language and possibilities in his book Eaters of the Dead. I wouldnt be surprised if many of his readers would not have known that it was Beowulf.
Poetry must be accessible to the audience. The author of this work was once at a networking event where he was discussing poetry with some business people. He had some samples of his own poetry with him. One of the ladies complained that she had never gotten the poetry in school. It had never made sense to her. In reading one of his poems, she brightened up. Now, this I understand! It always comes back to knowing the audience. If you have a limited and highly-educated audience in mind, you can get away with obscure references to Greek, Roman, or Sumerian myths and legends. If your audience is broader, refer to concrete things they know, like an umbrella:
You shield me from the cold rains.
Your spine is strong against the wind.
You open around me when I need you most.
I am protected by your love.