I like a fairly thickish scarf so here is what I do when I make my scarves.
First of all open up your tape as below, it will become quite wide.
To cast on, you literally put your needle through the tape, about two wefts down (remember in fabric weft is the row which goes from left to right). Be brutal, poke the needle through the tape, bring the need back to the front and about 1.5 - 2" (or if you are a young thing, about 5 cm) further on, poke the needle through again, you now have two stitches. For a skinny scarf you will need eight stitches for a luxury thick scarf you will need to cast on 12 stitches.
How easy is that for casting on?
Now start knitting your first row, remember to open up the tape, now as if you are going to knit put your needle through the first stitch, with the open tape catch about two rows down on the weft of the tape on the needle in your right hand and pull it through like a regular knit stitch. Now I warn you, this will take you back to when you first started knitting and no-one had taught you how to wind the yarn around your needle as you will have literally take the yarn between your thumb and forefinger to ensure that the tape is open.
As you continue to work, the ruffle will develop on both sides, making the scarf rich and luxuriant.
As you can see, it really is a different scarf, which all my friends have admired, which is probably why I have four more to make!