The first thing I would do is change your tags. You’ve written them like hashtags on instagram, but here you don’t need the # symbol and you don’t need to run your words together, so instead of “#acrylicpainting” it should be “acrylic painting”. Also make sure you hit enter after each tag, as it seems occasionally you have 2 or 3 tags in one.
Some of your items don’t have any tags, so make sure you add these as it helps items get found in search. It’s best to use all 15 if you can, but if you can’t think of that many, at least make sure you have some.
Next, a lot of your items don’t make any mention of size. If I’m buying a painting, at a minimum I want to know the height and width (and for your paintings, is that the height and width of the painted area or of the frame?). For your dolls I would want to see the height in either cm or inches, not just compared to a pencil as then I would have to search around my house to see if I have an unused pencil and measure how big it is. It’s great as a scale photo, which I see you have, but I’d also want to see an accurate measurement in the description.
Which brings me to the next improvement I’d do - photos. On some of your items you’ve showed plenty of different angles and used up all your photo slots, which is great, but on your paintings you’ve only got one photo. If I’m buying something online I generally feel more comfortable if I can see more than one photo, as it helps show it’s a quality item and that it looks good from all different angles… not just one. I’d definitely feel a bit wary about spending £95 on something if I’ve only seen one photo.
You might think a painting is a flat thing so one photo is all you need, but it’s nice to see the painting as a whole straight on, the painting from an angle so you can see how the edges look (particularly if on stretched canvas or framed), the painting close up so you can the detail, the painting from afar so you can get some scale for how big it is and the back of the painting so you know how it hangs.
You don’t have to do all those views, but it’d be nice to see a couple more.