Well, I'm a minimalist so.....

The first thing I would do is empty my closet totally. I would then take out the non-negotiable (those you mentioned that have meaning) and put those back. Then I would put all of the duplicates together and choose the "nicest" and hang up those. The others go into a pile.
If you have similar plaids, then do the same with those...
Then toss the dated clothes into a pile with the exception of classics....plain dark skirts, plain dress pants. white shirt...you get the idea
Take what's left and toss those that are in really bad shape.
Then you should be only left with your favorites. Make two piles, love and like. Hang up the loves.
The likes, go through and try on....there will be some that are less flattering than others. Nobody wants to look so-so in jeans, no matter how much you love them, so all of that goes into the pile.

What about the pile?......there will be some in very bad shape...they get tossed. There will be some in decent shape...they go to Goodwill. And the really nice ones go a consignment shop...

There you go.