How to wear boots that are slightly too big?

[sylvir]

I bought these really nice boots (on final sale), however, they are a size 7. I typically wear a size 6-6.5.

They are basically all around too big, length-wise and width-wise.

I'm wondering if there are any alternatives to things I can do to make them work for me? For example, do things like shoe padding exist? I feel like it should, but I've never had to look into it so I'm not sure.

P.S. I tried to wear just socks and it's still too big :\

Thanks in advance!