A simple textured pattern appears on the front center and outer part of the sleeves, remainder of sweater is worked in stockinette stitch. The sweater body is worked in the round from the bottom up as far as the armholes. The sleeves are worked in the round with double pointed needles/short circular needle from cuff to underarm, and then placed on the same circular needle as the body. The yoke is finished in the round with raglan decreases. While decreasing, two stitches from the body will be dropped, and then worked back up with a crochet hook with doubled strands of yarn.
This should be an easy pattern, knit and purl stitches with raglan decreasing, plus a little added interest with dropped stitches. Nothing too fancy, no seaming, just enough to accompany a beard without overshadowing it.