Fix a dropped knitting stitch
Use a hook to lift the live loop through each horizontal ladder strand in order.
Work the technique
Secure the lowest loop before it unravels farther. For stockinette viewed from its knit side, insert the hook into the loop, catch the lowest ladder strand and draw it through. Repeat upward one strand at a time; return the loop to the needle with its right leg in front.
Try it on a sample
Drop one stitch from a 20-stitch stockinette sample by two rows and recover two ladder strands.
Check and recover
Skipping a ladder leaves a long float. For a garter ridge alternate which side the strand is drawn through; a cable or lace crossing needs its own chart to reconstruct.