Generally speaking, I’d say things are going very well for you. You’ve achieved a lot so far. You’ve overcome the initial hurdle of getting things going.
Overall: Bear in mind that this can vary significantly depending on the season and current holidays. In summer, for example, printing is usually done less frequently. Let’s take a look at your 3D models.
Let’s take a look at some successful models. You solve everyday problems that are always in demand, and it’s easy to see how it works just by looking at the cover. You also seem to be solving problems that haven’t already been solved by thousands of others. Very good.
Let’s take a look at your latest designs, which now clearly prioritise decoration over problem-solving. So, your focus has shifted. In some cases, you are also attempting to solve everyday problems that have already been solved far more effectively by others. Your focus has clearly shifted.
So you’ve switched from solving specialized everyday problems to a shark tank that’s already completely overcrowded. Of course, people can give you tips on how to take better photos and improve other aspects.
Your main problem, though, is this switch. When I search for ‘CD/DVD spindle case’, only a few results come up, and yours is the first one. Well done - you’ve solved a problem that others haven’t yet managed to solve.
However, when I search for ‘nameplate’ or ‘watch stand’ now, I find thousands of results, many of which are clearly superior to your design.
That’s why it’s not much use giving you general tips, since you decided to switch to a field where you can’t keep up - and neither can I, by the way. Decorative items are a highly competitive market. For example, your watch stand is boring in comparison - you’re competing with those, and you chose it yourself:
I think you just need to refocus on your strengths, stick to your areas of expertise, and avoid areas where competition is tough.