Use crisp white paper, normal sized. If your poems look like they've been through the ringer, print or type out another copy. Inkjet is fine, as long as your ink cartridge provides fairly dark ink and doesn't smudge. Finally, put your name and address on one of the upper corners of each of your poems. Expect to wait.
Many magazines are understaffed and have massive backlogs.
Of course, there are always a plentitude of exceptions to the rule. Investigating in Poet's Market will reveal many high quality magazines that have very quick response times. If that is a primary criterion, then send your stuff accordingly. Otherwise, 3-5 months is not uncommon. Mercy me, but yes, expect rejection.