Itinerary Ideas for Southeast Asia?

Hello, I am leaving for Southeast Asia with a friend in three weeks. We are planning on traveling through Thailand, Vietname, Cambodia, Laos, and the Philippines. We are in Asia from April 25th-Aug 28th. We were planning on winging it but in order to get a Visa for Vietnam we need to know when we plan to enter. I would LOVE to hear some sample Itineraries from you guys. We were thinking Bangkok, Southern Thailand (beaches), Cambodia, VIetname, Laos, Bangkok, Philippines, Bangkok. We want to know where to go and the best (cheapest) ways to get around. Thank you so much for your help! xo.