The number one thing that people say in surveys about the experience of selling a home is that they wish they had started getting their homes ready sooner. Much of the focus is on repairs and improvements, for which there are, of course, other surveys. The last one I read said that the improvement with the highest return on cost during resale is replacing the garage door. Not the kitchen or the bathrooms, you should note, both of which are much more expensive and take longer.
We generally advise people not to undergo major work, if their goal is to sell their home in the upcoming season. Kitchens, master bedrooms, and baths are all things that you should do sooner than that, so that you have a chance to enjoy them. They are well known not to pay back completely upon resale, and the likelihood that you will choose exactly what the eventual buyers want is pretty small. I have seen homes with brand-new kitchens, where everyone who sees the home figures that they need to gut the kitchen anyway.
On the other hand, decluttering is never a waste of time. Maybe the advice to take out half of what is in every room is a little extreme, especially depending upon your own degree of hoarding tendencies. However, it is clear that making your home as generic as possible, within reason, will make it easier for buyers to imagine themselves and their belongings in the space. Decluttering also makes rooms look bigger, and conveys a feeling of serenity that puts viewers into a more positive mood. And removing stuff doesn't cost any money, or not much, even if you rent a dumpster or hire someone to help. Since it is the single best thing that you can do, we recommend it to everyone. If you want to see proof, look on line for before-and-after photos. You can even consider renting staging furniture, if yours does not add to the perceived value of your home.
The one downside to this advice is that it does take time, at least for most people, because they want to go through the clutter, not just pitch it or store it. The latter option should be considered, however, because many of us have found that storing many of your belongings for an extended period makes it easier to decide what you really need to keep, and what you can dispense with at that point. Good labelling helps in this regard, by the way, because it keeps you from having to go through every box when you do take things out of storage.
So, whether you want to start removing items from your home, throwing them away, or just stopping the future accumulation of new items, it should be on everyone's to-do list for 2017, even if moving is years away. Why save now what you will have to discard later? If you do plan to move this year, convince yourself that paying to move acquired possessions, store them, and move them again will cost money that could otherwise be spent on new furnishings for a future home. That should be good motivation to shed the old, and embrace the new!