The Vest is knitted from the top down and the scarf is worked in the round.

In order for the vest to fit the teddy best as possible, you need to make sure that your knitting tension is correct. If you have more loops on 10cm. section, you need larger needles. And if you have fewer stitches per 10cm. do you need smaller the needles.

I personally find it most comfortable to knit small garments on a long circular needle and use the Magic loop technique after the piece is joined in a circle.
If you also want to use double pointed needles, that’s fine.

I also encourage you to use the yarn you have at home because the vest and scarf are ideal leftover project.