If it's just updating furniture/decor that is quick and easy and you'll be up and running for 15 or 20k for a 4BR. 

We then furnished the interiors and decorated with a new theme to give a nice desert vibe to match the surrounding decor.

But I think the keys to success in either scenario are really the same: location absolutely matters, your pricing must be appropriate, decor and amenities absolutely matter, and you must be willing and skilled at treating it like a hospitality business.

Get an interior decorator to furnish and design.

My idea is to plaster the inside to make a decorative "nook."

I am trying to decide between 3 properties here in Atlanta to do an Airbnb arbitrage but I'm trying to figure out if each property is a clear deal or am I forcing deals by thinking I could decorate them and command a higher occupancy.Would love some insight.

Also use the "Enemy Method" to find out what your competition are doing, both financially and how they are decorating their properties.  

Invested in a designer to decorate the airbnb and build an extension to the deck to accommodate a stock tank pool.

One option is to rent out a fully decorated vintage airstream, or alternatively, construct a 40' RV pad with hookups and rent it out.

This was in a high-end area with costly homes, so my friend had higher quality decoratives and electronics.