A couple of years later and I know the answer. Well there are many ways to skin a cat some a quicker and neater than others.
Where I got to was a simple answer for most video production workflows.
1. The DVDs at the Rental shops are encoded down from HD/2k+ projects so they are able to get sharper and better quality SD DVDs than I ever will with an SD workflow.
2. Know what format you are starting in and what your finished format and medium will be.
understand a Package/CODEC/Bitrate(VBR or CBR)/Resolution
e.g .VOB/MPEG2/7600kbps CBR/720x576anamorphic
3. Shift the format of your video as little as possible in any workflow .
4. always scale down resolution from step to step, never scale up e.g dont start with a 400×300 pixel video and scale it up to 800×600, thats stupid.
5. choose the best quality 2 or more pass encoding setting. who cares if it takes longer to encode, your left with a much better quality video, at a much lower file size and all the motion will look smoother.
6. Adobe Premier has finally overtaken FCP as best editing tool. will recognise AVCHD videos out of Sony HD cameras without having to log and transfer them into Apple Pro Res 422 first. the finished youtube or DVD videos look much better because of step 3.