If you cannot say the offer in one breath, the letter cannot either
Write this fill-in: "You get [thing] so you can [result] by [time or next step]." If that sentence needs a meeting to explain, fix the offer before you study more formulas.
Match the letter to one reader
A letter for "anyone who wants freedom" will sound like 2008. Pick the person who already wants the result. The secrets download is a set of structures - they work when the reader is real.
Remove competing exits
Nav bars, related products, and three CTAs to different URLs leak attention. A sales letter should feel like a hallway with one door.