I think rendering is always a problem unless you have final cut x, my advice is to find the effects you want to use in your film by experimenting in small sections but not applying them all over till the edit is finished, then when the edit is finished and you know where you want all the effects apply them last then you can render over night or when your busy with something else instead of waiting around for the render. And after it has fully rendered then you can tweak sections and just render the parts you have changed. also make sure you have space on the computer or external hard drive for your render files!
Editor and Post Production Coordinator
I Love That Productions