I am going to add a filter organizer to a future Amazon purchase. This month I was without ND filters (as is normal for me) and I really discovered I wanted to slow down shutter for some wind turbines. I have no organization, carry the filters in original packaging, so this discourages me from making space in my backpack case.
I may have to invest in larger thread size ND filters. I bought mine 12 or 13 years ago when I had a lot of 52mm filter thread lenses. Today they are larger. I have a step-up ring to adapt to 62mm, and that works on some lenses, others will vignette.
Oddly I bought a 77mm variable ND and circular polarizer combo filter in 2019, and I don't believe I ever really used it yet. I have misplaced it a couple of times so it was missing for like 2 years of that time. Sure wish I had it in the bag a week ago.
This is the wind turbine scene I was working at. Handheld at 1/8s and I needed to be about 1/2s on a tripod to get the windmill motion I wanted. I was badly overexposed.
This is the next photo in series, 1/200s with better exposure. But no motion, so not as dynamic.