The classic error when beating in light winds is to over sheet the jib. A telltale on the leech of the jib will enable you to avoid this. Once flow has been disturbed over the leech it is often necessary to let the sheet out a long way to get the telltale flying again (the helmsman will get unhappy bout this but ignore him). Once it is flying sheet in slowly, so as not to disturb airflow.
In light winds and a swell you need to get as much power inot the rig as possible. Don’t try to point, keep moving. It is better to moving in the wrong direction than stopped!. Within reason let off kicker out haul and halyards and don’t over sheet.