Which friction hitch to use when ascending a rope?

The Prusik knot is the standard and most reliable friction hitch for ascending a rope, favored for its ability to grip from either direction. For easier sliding, the Klemheist or Schwabisch (asymmetric) hitches are preferred, as they are less likely to bind and easier to release after being weighted. 

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VT prussik is my go to when I don't have an ascender or micro trax on me.