There are very few absolutes in sewing. This is why I love it so much; there is so much room to play and have fun. However, as we learned so long ago in the sandbox, in order for everyone to have fun there are a handful of basic rules that we all must regard.
First rule: Keep with your grain. It doesn't matter which way you go, just keep going that way. If you make an entire garment upside down or sideways, as long as it matches itself everything will be fine. But if you try to make a sharp turn halfway through everyone will know that something is wonky. Now, if you want everyone to notice that you were daring enough to change course halfway through, go for it. Think of it like this; if you're an art major and show up for honors physics, people will notice. If you can do both, great! You go, girl. But make sure you know what you're doing because if not everyone will be paying attention when you bail.
Second Rule: Never loose your center. Ever. Mark it. Write down where you put it. Because you will some day find yourself happily pleating or trimming over on the side bodice, not a care in the world, when you realise that your beautiful accent doesn't match the other side. All the floof in the world can't cover up the fact that you forgot where you going because you were having so much fun getting there. It's not the 80's, nobody is going to believe that you just really like assymetrical blouses. So every once in a while, stop what you're doing, get your bearings, check your notes, and locate your center. Because, like in life, not everything is available for a do-over.
Third Rule: In the end, you're going to need closure. Now, there are many styles of getting there and most of them are not wrong. Just know what it is that you are getting into before you start in that direction. Some of the most satisfying closures require that you plan far in advance. Bound buttonholes, for example, have to go in first. Invisible zippers too. So if you want to impress you have to make a plan. Now, if you're the type that likes to live on the edge, there are all sorts of fun possibilities for you as well. Buttons, snaps, hooks, ties, zippers, can all go in at the last minute. I'm not saying what kind of closure is best for you, I'm just saying that eventually you're going to be looking for it, so you may as well keep that in mind before you start. Or you could just wear a belt.