amateurish work; unprofessional craftsmanship
Refers to work done by an amateur, often implying a lack of skill or polish. Can be used self-deprecatingly.
This is amateur work, so please don't expect too much.
The shelf he made is amateurish, but it has character.
素人 means 'amateur' or 'layperson'; 素人細工 specifically refers to the work or product made by such a person.
玄人 means 'professional' or 'expert', the opposite of 素人.
Compound of 素人 (amateur) and 細工 (workmanship, craftsmanship).