Gambeson
Poor Marchers may wear just a plain coloured padded jack or gambeson as their only armour. Wealthier yeomen have jacks in their household colours and mail or plate over the top if they have it. Richer people will add chain and maybe odd pieces of plate, like a gorget on top, while the rich will wear a full harness of plate. Beaters usually wear lighter armour, either just a padded or leather jack or else a leather tunic like the ones worn by the Rangers in Lord of the Rings.
Padded Jacks are fairly simple, though time consuming, to make from cheap calico quilted to 'batting' used to stuff quilts. The very simplest way is to make a T-Tunic as detailed in the men's clothes section, and simply sew the batting to the calico panels in straight lines before sewing the pieces together. More historically accurate gambesons can be made by sewing channels into the jack and stuffing them with fabric.