Everybody does it in different ways, I would imagine. When you have only a few submissions/acceptances/rejections, a folder of paper works just fine..or did for me. Soon, the folder was filled with scribblings of what poems were rejected HERE and accepted THERE and I could make no sense of it.
About two years ago a friend set up an Excel file. Three tabs. Accepted. Rejected. Submitted. On each page is a place for poem name (or haiga jpg name), Journal submitted to, Year, date, and a column for extraneous information. When a reply comes to a submission, all I have to do is right click to the left of the line, highlighting it, choose 'cut' from the drop down menu, hit the accepted or the rejected tab, and right click to the left of a blank line, then paste. So easy!
Since these can be 'sorted' alphabetically, it's easier to double check on a poem before submitting, too.
What method do YOU use. Tell?