Get rid of things you don’t need or use.  Reduce, reduce, and reduce some more.  If you have to keep it because of sentimental value store it in the garage or attic.     

Make a collage of pictures that speak to you.  You can do this with magazines or online on Pintrest or  Make a list of the elements that you would like in the room like the type of fabrics, materials and paint colors that speak to you. You are not copying anyone.  You will use this to find out how you want your end result to look like.  It helps with vision. 

Buy an architectural scale, measure the room and furniture you are going to use and make cardboard renditions of them in ¼ inch scale using a cereal box or other light cardboard material. Make sure that you measure the windows, doors, and fireplaces correctly.

Draw your room in floor plan view, as if you were looking down on it from the sky. 

Find your focal point and design in a way that features your focal point.  Focal points are usually a window opening, art, or fireplace. 

Using tracing paper note the focal point and the traffic pattern that exists naturally and place your furniture accordingly.  Play with different configurations until you find what works for you.  Trace over where you place the furniture or take a snap shot and upload to your computer or email it to yourself and then print the different configurations.  Once you find a good configuration you can draw it more precisely so that you know that it fit’s correctly in the space.   If designing a living room and it is larger consider 2 or 3 different seating areas, one for tv, and others for conversation, lounging, or reading.   

Remember that you do not have to plan a room all in one day.  You can take several days or a week to consider your options.  Allowing yourself time to consider your options may just save you a headache later. If you are not happy with the configuration maybe that means something is missing.  You may want to buy another piece of furniture to replace something that is not as functional in your space as you would like.