How do you determine whether or not something you own is junk?
The things you love and use are easy to identify. For example, your favorite pair of earrings, your child's baby book, the CD you listen to twice a week, the teapot you use daily are not junk. They are loved and/or used frequently. You don't have to explain to yourself or to others WHY you want to keep them.
The things you really dislike, too, are easy to identify. Out-of-style clothes, a too-heavy dutch oven, that TV your ex-boyfriend bought for you on your 20th birthday. You can easily get rid of those things when you have your supplies (trash bags, donation boxes) handy and a way to conveniently get them out of your home (a donation truck scheduled to drop by, you neighbor's garage sale next week-end, your own scheduled trip to drop off donations at a thrift store, etc.).
Those maybes are the tricky things. How do you determine whether or not to keep them?
A simple test is this: if you have to spend any length of time justifying why you own a particular object, then it's probably junk. If I were standing next to you helping you declutter, and we came across the needlepoint pillow your cousin gave you (which you don't like), you would probably try to justify why you've kept it for twelve years and how hard your cousin worked on it and that you and your cousin were best friends for years, blah blah blah.
If you have to explain why you are keeping it, when in your heart you don't like it, then it's junk.
Quit wasting your precious time reminding yourself why you should keep it. You shouldn't keep it. Trash it, recycle it, or share it.