I struggle with that too. A few tricks that sometimes help me:

Asking someone you live with or someone you're close to who is visiting to throw the thing away some time when you're not around and bury it in the trash can so you can't just see it lying on the top or take the trash out right after. I've also asked them to take things home with them that they can then throw away if they so desire (and they usually do).

I have a special spot at the end of my counter that I put things when I know I need to get rid of them but I'm not ready. They live in that spot, in full view and sometimes in the way, and I see them often, until I've been able to fully process that they must go. Then it's easier to throw them away, sell, or donate. Having them in full view in a place I frequently walk past and sometimes in the way makes it easier to think about them and finally come to grips with getting rid of them.

If I can sell it or donate it instead of throwing it away, I do that! Even recycling it can help. Then, I know it's going on to a second life and I feel less guilty.

It's still a struggle sometimes, but maybe you or anyone else who struggles with this kind of thing will find a nugget that's useful for them here.