I work with interior designers all day long (have for 27 years). In the movie biz we call them production designers and set decorators. many of them decorate on the side and are not cheap. Do you want to pay someone $5k to help you pick out $2k worth of Ikea furniture?
It's something you can do yourself. We put together 'concept boards" to show the director. Nothing more than pictures, paint swatches, fabric samples mounted on foam core boards to do a presentation. An easier way would be to use Houzz, similar to Pintrest but interior dec oriented.
Houzz - Home Design, Decorating and Remodeling Ideas and Inspiration, Kitchen and Bathroom Design
The best way to approach it is to find the furniture style you like, something timeless, nothing too current that is going to look outdated in 10 years (think that turquoise/ desert rose southwest look that was so popular in the 90's). Get your sofa, chairs, tables, etc in subtle tones (Beige, sage, gray, etc) and make your colors "pop" with the accessories (throw pillows, lamps, window treatments, etc). This way down the line you can keep current with "in" colors that change every year or two.
When we decorated the beach house on "Something's Gotta Give" it was actually featured in Architectural Digest. EVERYONE in the Hamptons wanted their house to look just like it. I'll see if I can find a photo.
But whatever you do, don't ever use the words "fun" or "whimsical" to describe furniture/ accessories. Just makes you look like a gay douche.
