After you've removed the clothes that don't fit or are no longer in style from closets and the furniture you had in college, the house should look bigger. Move or toss furniture to create a better traffic pattern. Paint is the best bang for the buck. Sorry, but plain vanilla/beige still goes with most everything. If you're not a real interior designer, avoid getting too artsy. What looks cool on HGTV may cost you money in upstate NY.
Once you've tossed the junk, everything is spotless & all repair issues completed, the only thing left is price. All things being equal (they never are) the only way to to sell faster than the market average is with a better price. The opposite is also true ie; if your home has been on the market longer than the average ...its overpriced.
There's a ton of free advice and checklists on the internet about getting your home ready for sale. Become an informed consumer and when you think you're ready, call a good full-time agent to see how your home measures up to the market competition. Good Luck!
Definitely make sure you remove clutter. Put away laundry, toys, supplies, and so forth. Organize your closets so they look bigger. Sometimes buyers have a hard time seeing beyond the clutter, so presenting your house in the best possible way is important! Consider rearranging or removing some furniture, if necessary.
Is your house hasn't been painted in many years, or if you have bold colors or wallpaper, consider painting with neutral colors in order for your house to appeal to as many buyers as possible. Also, if you have any worn carpets, consider removing them or replacing them.
Remember, you never get a second chance to make a first impression!