If your home is getting too crowded with things here and there it's time to give yourself some space and air to breathe. Don't start with the difficult things just yet. Take care of all the obvious trash first so you will feel a sense of accomplishment after a while. Then you could continue with the things that you can part with without breaking your heart. For instance, you could have clothes from a decade ago. Or, you could have piles and piles of newspapers and magazines still lying around.
Along the way you are going to come across items that you no longer need but you don't have the heart to get rid of. The thing is you keep most of these items because of sentimental reasons. For instance, you could still have your 3-year old daughter's old booties and other clothes until now. What you can do instead is to choose the favorite items among them. Perhaps you could pick one complete set for each year and get rid of the rest. Then you could put them the small items in a show box frame or put everything in one container. If you can't bring yourself to give them the rest away now, simply box them now. Then after a month don't open them anymore. Just give them away to charity.
If you want to raise money too, you can sell unwanted items online. You can also sell them through garage sales or through the flea market.