I won't mention names, but I recently came across someone who, from her comments, was clearly using very old copies of magazines for her research. It might seem like a money saving idea to use the copies you found in the cupboard under the 1973 tax paperwork but it'll cost you in other ways.
There's no point crafting the perfect story for a magazine which no longer prints fiction, or which now has very different requirements in terms of length and/or style.
Most of us can't read every issue of every magazine, but it makes sense to read several current issues of whichever ones we're targeting.
Check any notes, lists or spreadsheets you've made for yourself too. Are all the details correct or are you saboutaging your chances by submitting work the editor simply can't use?