multi screen on final cut express

I recently started my filming and started editing. I decided try and create a multi screen. I watched a tutorial on YouTube on how to do this as this is a new skill that I am learning. I found this very difficult to grasp a hold of to begin with. I have started to learn the basic skills of how to create multi screen as you can see from the image above.

However I was not happy with the final outcome because as you can see it is not particularly neat. I am also planning on re-filming these shots because my artist is not sitting in the centre of the frame how I would like her to but I thought I would use these shots as a practise to learn how to use the multi screen.

The image above shows what the sequence looks like on the track. I think that these test shots were a good idea however they have given me an idea of how difficult it is going to be to create the multi screen and that I need to allocate myself enough time so that my music video is of the standard that I want.