Dust collectors are not for me. But I tend to decorate for most holidays and if not just the season.
The extent of my decorating takes 10 mins except for Christmas. MIL and Mom guilt me into it at times and sometimes browsing a store like Christmas Tree Shop makes me pick up a few things. It's usually a wreath for the front door and maybe some place mats. Nothing crazy.
I've decorated for Christmas, St Pattys , Easter, and Halloween. I wasn't planning on decorating for Easter but apparently we're hosting this year. After Easter I have these teal and yellow place mats I put on the dinning room table for Spring/Summer.
My MIL goes all out for every holiday. At the moment it looks like Easter threw up all over her house.
V and I don't really decorate for holidays. We have for Christmas but that only takes 5 mins. We don't have a lot of decorations that don't serve a purpose. But that's to prevent things becoming all clutter. We do have dried flowers, picture frames, and rocks. All of those are sentimental though, so I don't mind them!
I go all out for Christmas! I have a big artificial tree and I've been collecting Christmas ornaments since high school. I like getting a new ornament every time I go somewhere fun. FI and I have one from Disney World that we got on the day he proposed. I think it's my favorite. It's very simple; Mickey and Minnie standing on top of the standard red ball, and Mickey's hiding flowers behind his back to surprise Minnie. I love finding ornaments that capture the trip! My tree is almost full, which is awesome.
FI loves Halloween. LOVES Halloween. We go all out for that, too. He likes to do the whole fake spiderwebs thing and we have a headstone set that we put up in the front of his townhouse and it has zombie hands that you can stake into the ground in front of it so it looks like a zombie is rising up from the dead.
Re: Knickknacks and seasonal decorations
I decorate for Xmas and Halloween (I fucking love Halloween). But valentine's day, st. Patrick's day, Easter, 4th of July.... Nah.