These are some of the tools I use to assist with effective property advertising. More is more in advertising. 

aspen times
Find Rentals or Roommates by Going to the All Classifieds Page
post independent
The All Classifieds Page can be found if you go to one of the dropdown categories under classifieds first.
find property manager on facebook
The following groups are the best for finding rental opportunities: Roaring Fork Rentals and Roommates, Roaring Fork Housing and Advice, Roaring Fork $ Beyond Classifieds, Roaring Fork Swamp, Deals of Aspen, Rifle& Surrounding Area Classifieds, Western Slope Rental Properties. I post my rentals on my business page.
hotpads
Hotpads is a Zillow group product where you can see rental ads.
craigslist western slope
https://westslope.craigslist.org/ serves our area. It also serves the entire Northern, Southern and Western parts of Colorado so you have to wade through the posts or filter geographically to see Roaring Fork Valley offerings. Occassionally there is a gem. We post here.
zumper
Zumper is a Zillow group product where you can see rental ads.