I am editing- well doing the twice yearly reading of submissions for Tears in the Fence- I am the Australian editor of the UK literary magazine. Although I cull I don't have absolute final say of what is selected- but there's a good chance. What makes a poem stand out? Well that's easy- good writing. But what is good writing? Even though it is free verse it should still have rhythm and as it is read it should sound like poetry in that inner ear. Difficult? No, a great poem shows me something new in the world- it should use concrete words- unusual words in new ways. Give me precise nouns and precise verbs. Allow the emotion to be liquid, a blood vessel pumping the breath of the poem with vigor and energy.
Here's a couple of cosmetic hints :
don't send blurred photocopied sheets of poems, do put your name and address on each page- believe me submissions appear each time without this basic requirement
Read what is currently being printed- try these poems for emotional factors, the use of concrete nouns and verbs
Look at titles- which propel the poem along? Which titles become an intricate part of the whole poetic read and re-read, which titles do nothing for the poem?
All this is valuable research for your own poetry writing and success in the small literary press publications arena.
Keep sending work out.
Keep analyzing contemporary work.