Sometimes you have to get a bit selfish when you want to get organized. You may not be able to convince your significant other/"the other person" that:
"Hey, we need to live a little bit better."
Perhaps they are happy with the way your home is set up. Then again, they could just be a little embarrassed to acknowledge there is a problem and asking for help would just add to those negative feelings.
Once confronted with this situation, try to fall on the old adage:
"Lead by example."
Look around your home and find an area you can conquer the organization of your stuff without the help of others. Maybe it's a kitchen cabinet, your bathroom counter top, a sock drawer or your nightstand. Tackling one small organizing project successfully will give you a sense of accomplishment. Following up with another small project will get your mood rollin' toward pride in your progress.
Choose your areas to organize that involve only your items and interests, if possible. That way you are not interfering with "the other person" in your home. Hopefully they'll see you are feeling a bit better, able to find your keys quickly and overall just more relaxed about your own stuff. Maybe, just maybe, they will begin to clear up their areas too.
You cannot change who people are, though you can alter your reaction to them. If you are feeling more relaxed in your home, it will show. Yes, you may get frustrated at how this "other person" lives, but you can have solitude in your organized area.
If it took several months, or years, to lose control of your home, it will take some time to regain the organiziation again. Be patient and believe that you are working toward success.
Get a bit selfish. (there's nothing wrong with it)
Believe you can get organized.
Make it happen in small projects.Enjoy your organizing successes, no matter how small.
You are doing a great job!
What area of your home can you organize for yourself?