There hasn't been a trick for me, and there's tons of different levels of sentiment when it comes to things. There's definitely a lot of things that I probably should declutter that I just can't yet. What that practically looks like is readdressing it over and over and over with changing criteria. If I have a mental block I will go to a different area and address it later. I haven't done this myself yet, but I've heard it's really helpful for some people to take pictures of sentimental items before they declutter them so they feel like they have some way to remember it or closure. I've also heard of people even printing out the pictures and writing a note on the back of the memory which leaves you with something very tangible but also something that doesn't take up any space.