Hanging pictures in the house - options?

I know this is probably a silly question but I really have no idea right now. In the past, I always just hammered nails into the walls. Over time, I've become a bit more skeptical about that. If I want to change positions later, I'd have tiny nail holes all over the walls.

How do you do it? We have wallpaper. I've read about [Nano-Band], supposedly it holds pictures very firmly, but there are very divided opinions on how well it can be removed again. I also don't want to avoid a nail hole only to end up with a hole the size of a piece of tape in the wallpaper.

There are those rails, like in the [Galerie]. You can change pictures as you like. The rails are simply attached directly under the ceiling and stay there.

Eventually, it's time for the first hole in the wall :D Small (nail) holes can easily be filled with paint. If necessary, use some putty beforehand.

The first nail holes and anchors in the new house already hurt,
hanging the next picture on the same nail usually helps,
alternatively a bit higher, then the hole is gone immediately

That's what the favorite person is for, who holds the pictures on the wall until their shoulders burn...

At some point it's time for the first hole in the wall :D
Small (nail) holes can be easily filled with paint. If necessary, use some filler beforehand.

Here comes the next problem - I have leftover paint (the wall is not white) in a bucket on the roof. How should I store it best? Is it true that I should store it away from light?
It's not protected from light on the wall either, if I paint over it in a year you might see a color difference?

The first nail holes and plugs in the new house already hurt,
hanging the next picture on the same nail usually helps,
alternatively a little higher, then the hole disappears right away

I've already made the first mistakes. Hung elongated pictures quite high up, then I didn't like them there after all. Now I want square pictures there. Hanging them on the same nail would be too high. And if I hang them lower I have 6 nail holes above the new pictures. o_O

That's what the favorite person is for, who holds the pictures to the wall until their shoulders burn...

I thought about that at first too, but then I'd have to change the kid myself. :P