Bottom up. Roof is too steep, flue is too high above roof line and has a support that would have to be removed to take a section off, and I don't do anything beyond step ladder height if it can be avoided:
Bottom up, have clean outs on both chimneys ... works great with the soot eater... First thing I do is add all the poles sections until I feel the cap..... Then I start spinning the whips and knock anything in the cap free and just work my way down... couldn't be any easier...
Clean from above because it easy access and ya can get a good look at the worst part upper. http://firewoodhoardersclub.com/forums/index.php?threads/last-chance-to-sweep-today.1866/
Both, I don't have enough rods to reach the whole 35ft, and the 1/4 inch rods tend to flex/bend a lot after 6 sections.