DH & I put our house on the market earlier this year and in preparation to show it, we had to declutter. We are not done, we got burnt out and never really got back to it. I guess the best declutter for us is going to be when we have to pack to move! I don't keep a lot but DH is kind of a pack rat. He thinks he can repurpose everything or fix everything. I have to do a lot of going around behind him and cleaning up behind his back. He gets mad at me for a few hours, but gets over it. He gets overwhelmed by the stuff he had to clean out. I think he was actually surprised by how much STUFF he had around and after a yard sale, craigs list, about 20 trips to goodwill, the dump, with our trailer, he is starting to throw more away now.
I wish I had some tips & tricks for you, but just muddle through and you'll be so happy you did. Be realistic too, on what you are truly going to repurpose or not. I found that our good intentions of repurposing things from years ago didn't happen and I finally just got rid of those things.
Have fun and good luck to you!