I watch higher level games, and I see heroes slow down the creep wave to place it more on their side of the map. When I try it, I can't get the creeps to get caught on my hero. What am I missing here?
When you stand in front of a creep he will try to pas on your left/right side you need to constantly move slightly left/right so you restore them on the main path and without scattering them so they can block themselves(rest of the group behind them).
Blocking gets easier with larger heroes(pudge,lucifer...) since you have to maneuver less,and if hero is slower you will less likely move too far on the sides which could make the creep pass by you and ruin the block.
Pulling you can attack the neutral creeps(side lanes) and lead them close to your creeps on lane making them fight behind your tower and delaying the creeps progress.
Hero Skills (this is prohibited by some tournament rules)