The single most common beginner mistake is cutting strands too short. The Rope Consumption tables on the Flogger page give you per-knot consumption in inches and centimeters; the trick is to add them all up before you cut anything.

Worked example for a six-strand flogger with one Matthew Walker transition, a 7" Half-Hitch handle in 1/4" rope, and three Blood-Knot-2 per fall: each strand needs MWK6 (~6.25") + the handle share (~16" per strand of 1/4" rope to cover 7" — divided across six strands) + 3 × BK2 (~12") + your desired fall length + finishing slack.

Always add 10–15% finishing slack for the cap and any mistakes. Rope is much easier to cut shorter than to splice longer.