Put some extra weight under not only your seat, but both...
Flew with a couple of guys who only weighed 115lbs or so and we always added weight under his/her seat (expecially on solo flights)
Being fat bastard that I am - I only need to floor collective and leave it there prior to flare when practicing autos solo.
Low-time pilots should practice w/instructor until maneuvers is mastered, but I guess you've heard this already.
later