I've been sort of a researcher you could say in the realm of organizing for the last seven years professionally. While every situation is slightly different, I do tend to see patterns and common problems amongst those I work with to get organized in their homes. I try to catch and correct these if possible. They simply don't help the process of organizing for long-term results. Below are the most common mistakes to avoid. Are you doing any of them?
1) Buying Storage Containers or Organizing Systems before purging
I can' tell you how many people I've worked with that have more containers than they know what to do with. Although they may have had the best intentions to be used to organize something, the containers actually become clutter if not being used. It's usually never a problem for us to find something to use that they already have to organize their stuff. I know it's super fun and tempting to go to Target or wherever and get a brand new storage bin with matching top... Or, to purchase that cool shelving unit or organizing drawer set on wheels you saw online. It oftentimes looks like it would help you keep x, y and z organized... and if it's on sale.... why not? Right? Not usually. My advice: RESIST! At least until you get a handle on your belongings first. Probably the most common mistake I see is when people buy storage containers before they have actually have gone through the items they want to organize. It might be more fun to buy containers, but doing it first is skipping a step. It makes organizing much more difficult because you may not have bought the best solution for your needs. Containers may be too big or too small once you've gone through and decided what you really want to keep. It's best to purge items first, and then see what's left to organize. A proper assessment of what you want to organize, how much or how many, and where you want it organized are pieces of information you need the answers to. This will ensure any purchase will be the best fit. Also, many times you might already have something at home that would work just fine. This saves you money and time. If you really need something new, you can reward yourself after you've purged. So, purge first, then search out a container or storage solution.
2) Starting with something that is more difficult to sort though (Memorabilia/Photos)
It's best when just getting started going through things to start with something that is easy. This means going though something that you don't have a lot of attachment to or can easily make decisions on without getting caught up. For instance, a great place to start might be your fridge. Throwing out old or expired items doesn't take a lot of asking yourself questions like "do I really love this?" "do I want this?" "where will I keep this?" It simply either stays or goes. You could move on to the pantry next, or tackle something like a pile of magazines. A common mistake I see when people are going it alone, is that people want to start with items that cause a lot of emotional heartache or are difficult to decide on. While I'm experienced to help people go through these types of things, going though items like this alone can be really difficult, especially when just getting started. It can stop people in their tracks and make them say "nope, organizing is too hard, too painful, too overwhelming." It can be very overwhelming at times, which is why you should simply avoid these items until you gain some practice and confidence. Learning to trust your gut and heart in the matter of decision making while sorting through items can take a little getting used to. Going through items of a loved one that has passed away or photos and memorabilia are common examples I'm referring to here. It's best to sort though sentimental items once you gain some momentum and have practiced your decision making process.
3) Leaving donation boxes and bags sit for too long
Once your decision is made to get rid of something, get it out of your procession as soon as possible. Many people don't follow through on this last step fast enough, and end up leaving bags or boxes sitting in their house too long. As far as I'm concerned, if it's still in your house, and unwanted, it's clutter. And although it might be nicely bagged up, it might start to mix in with everything else. If you need to record things for taxes, do that immediately following a purging session or as you go. Take a picture with your phone if you like. But if you don't get the items out in a timely manner you might forget what you decided you didn't want. Unwanted things might make their way back into the mix of things you do want. Getting items out of your house and into the car as soon as you can is key. Make a drop off on your way to something else, or at least clear them out of the back seat before the next time you have to pick up groceries. Your car is an extension of your house. Keep it clutter free as well so it's ready for the next load.