You can do tests to see what you actually use. For the sake of common terminology, let's say that everything you take on a trip is in your "container". And inside your "container" you have three "sections" - "section 1" for most used, "section 2" for lessor used, "section 3" for rarely used.

On your first trip, pack everything into "section 1".

When you get back, look at section 1 and move everything that you did not use to section 2. On future trips, you will first take everything from section 3 that was unused and totally remove it from your "container". Next, you would move everything from section 2 that was unused to section 3. Last move everything that was unused from section 1 to section 2. But after only your first trip, none of those lower priority sections would have had anything in them, but they will populate over time.

After you have finished the above described "demoting" of things from 3->junkpile, 2->3 and from 1->2, then you move on to "promoting" things. Anything that you used on your trip, no matter what section it came from, gets moved to section 1.

For things that need to be refilled, washed, or otherwise replaced - substitute a note saying what that item was and put the note into the appropriate section in place of the actual item. Replace the notes with their corresponding items right before your next trip.

If you found you needed something on your trip that you didn't have, when you get home immediately add it to section 1.

You will also have some "never demote from 3->junkpile" items. IMHO, you wouldn't want to remove your first aid kit just because you happened to be accident-free for three trips in a row. But try to keep these "protected items" to a minimum, otherwise it defeats the whole purpose of this exercise.

And there will always be a few "need to add" items. For example, if your last three trips were in the summer, your container would probably not contain the down parka that you need for a February trip!

And you will find that as the start of a trip nears, much of your packing is already done for you, because your container already contains lots of stuff from previous trips, and written notes for stuff that needs to be added.

How you physically implement your "container" and your "sections" is up to you - these might be bags, suitcases, boxes, ... whatever.