Schools differ in their feelings towards reapplicants. Some schools, such as Wharton, confess to being extremely interested in reapplicants. For other schools, such as HBS, I might suggest you skip a year before reapplying. In general, the key to a successful reapplication is demonstrating progress since your last application. Show that you have been progressing professionally and personally and are now a more qualified candidate. I recommend that you apply when you are most ready and hope to not go through a reapplication process, but know that if you do, it is not the end of the world!