You can do proper work which is display work. I never have had a pointless poster on display.
I have some year 7 essays on display explaining why William won the Battle of Hastings alongside some photos from a lesson we held in the woods. This is work they did at the end of last year so it acts as a guide to my new year 7s - this is what you are aiming for. This will come down and be replaced , but as you say we have only been back a few weeks.
I have some a Philosophy timeline for my A level students.
I have a GCSE display on Wealth and Christianity, featuring some Lego Bible passages, some teachings from Christian denominations, the class have then given their views on a post it note that are placed on the display - this was a plenary to a debating lesson.
I have a second GCSE display on the HIndu varna system which is mainly information and then has some photos of students dressed up as member of the varnas and some colour photocopies of exam answers they have done on this topic.
I have an A board which names students who are working at an A with examples of their work. Next to that is an RE in the news board which features articles mainly bought in by the students,
I have a year 7 display on India, includes a map onto which that have marked special places with examples of their research and newspaper front pages describing Alexander the Great's entry into India. There are also some settlement maps on there.
I have a year 8 display which features photgraphs of our active philosophy lessons, some collages they did at home and some colour photcopies of assessed pieces of work.
I also have a general praise board which feaurures photos and quotes from my philosophers of the future, exanples of outstanding work and merit charts.
THere is also a tutor board featuring lots of photos, tutor news exam results, merit tables etc.
Displays should be a mixture of celebration, information and showcasing work, there should always be something up and it should never be a pointless poster.
I also have glass cabinets full of artefacts, inspirational quotes on the walls, mood lighting and plants. I could not bear to teach in a sterile unloved classroom.