I'm only a novice knitter myself but I'm pro when it comes to Tom Baker (12th Dr).
I'm currently working on my first project a Dr Who scarf as well. I'm using a mix of Red Heart brand and Vannas Choice both full worsted for my scarf. I'm using only one strand and using garter stitch only. The pattern I found called for 60 some stitches I found I needed 50 or less I think I've actually got 49 stitches (thinking about it now I should have made it 42 cause everyone knows that's the answer to everything) I digress.
I pretty much chucked the pattern other than using it for color swaps.
Depending on the season he wore different scarves and there were a few variations including "stunt scarves". The most notable is the 12 foot long multicolored bad boy which is what I'm currently doing.
Now back on topic. Using a single strand will give you the proper lay for the scarf, if you go back and watch a few episodes you'll notice how the scarf doesn't stand stiff on his shoulders but has a rather nice lay to it, or drape. I found that I'm getting about 8 - 10 rows per inch and in fact I stopped counting rows altogether mostly due to my being a novice knitter and planning out my color swaps the best way I know with my skillset. Some colors are shorter than they should be and some a bit longer, all in all doesn't really matter.
TaraWheeler has some excellent videos of making Dr Who scarves up on Youtube. I think one about color change the other on tassells, in both you can really see the stitching as well as how the garment moves.
Been working on mine a bit over or under 2 months and it's about 5 1/2 feet long.