I first have to ask why would you massage all the meridians? More clearly, where or what did you read that indicated massaging all of the meridians would be beneficial to whatever health issues you are trying to sort out? I ask because I am unfamiliar with any system that would recommend massaging all of the meridians at one time. Certainly there are some qigong exercises and mild rub down techniques that work on the meridians. And I can see some benefit to just working the entire body. Generally, however, if you are trying to treat something in particular a more specific approach will lead to better results.
There are many systems of oriental massage which use the meridians (shiatsu, tuina, and various others meridian massage, etc.). Proper use of these systems, however, requires various diagnostic techniques to figure imbalances between meridians and then use the flow of the meridians to tonify or remove excess energy in specific meridians. Without knowing what you are trying to treat, it's hard to recommend what you should do. I doubt you could make yourself worse by doing this, but properly applied you could make yourself much better.
Generally, going with the flow (following the numbers in succession) of the meridian is tonifying and against the flow is dispersive. You might, for example, disperse the liver meridian and tonify the spleen to help with digestive and energy issues from liver excess. This would require some aspect of diagnosis which can come from the tongue, pulse, and other tools. I would suggest you consider reading some of the shiatsu texts in our bodywork resources section. These texts will help you approach your self-healing with massage and acupressure in a more focused manner. Personally, I think the ones by Ohashi are the best for beginners. Consulting with a practitioner for techniques specific to your case is also recommended.