It's actually quite easy. Something along the lines off "she/he examined the hand holds, foot holds, looking for the best one to reach to, to balance and continue the climb. He/she reached up, stretching their arm out to its fullest extent, just short, skimming the edges of the hold. "Just a little bit more" She/he cursed, and stretched as much as they could, grasping the hand hold, and pulling themselves up, finding a new hold for their feet, and balancing carefully, shifting their weight...