The first thing you must come to grips with when you put your home on the market is that you are now living in a "staged" home. Whether you have your home professionally staged or not, you will need to change how you live -- at least to some degree.
De-Clutter -- The de-cluttering process can be a major challenge. Remember you will be moving so start packing those items you won't be needing in the near future. They are going to need to be packed sooner or later so now is the time! Label the boxes carefully (by room) so you will be able to find what you are looking for in your new home. It is also a good idea to store any items of great value -- either sentimental or monetary. There is just no reason to risk an accident during a showing or open house.
Buyers will understand neatly packed boxes in the garage or basement but they won't be able to see through clutter or they will be so interested in your "stuff", they won't see the potential your home has for their family and life style.
The main purpose of de-cluttering is to allow buyers to be able to envision their furnishings in your home, to give each room the look and feel of spaciousness, and to allow the buyers to see the great features the house has to offer. Buyers need to be able to "live in" the space, not to be distracted by how your family lives in your home.
Notice when you are looking for your new home, how other homeowners have prepared their home for a showing -- whether it is a positive or negative. Then take that information home with you and look at your home as a new buyer would.
In our area at least, I feel that removing all of your personal items is a mistake. It can be just as distracting to buyers if the house is too sanitized and there is no evidence of the family that lives there. It can be a delicate balance and it is better to err on the side of too de-cluttered. So take down the wall of family pictures but leave a few decoratively placed pictures throughout your home.
Also, when you are in the de-cluttering process, remember to take into account where you will be moving. You may just not need or want some of your current possessions in your new home. There is always a charitable organization that would love to have your "extras".