Autologous blood doping, Hematide, HGH. Microdosing of other products, and hiding from testers during "peak" doping hours. Potential use of Repoxygen and stem-cell gene doping at the highest, and most well funded level.
That, and anti-doping controls are not very effective; error heavily on the side of the doper.
Even the biological passport isn't very effective of a deterrent to most dopers.
Yes, the sport is probably cleaner than in about 2002-2004 or so, when probably most of the top 50 finishers in major races were later tied to doping one way or another. But clean? No.