De_novo puzzles are puzzle where only the primary sequence is known.
A prediction of the secondary structure is often given in comment with probability that each amino acid is a part of a sheet, an helix or a loop.
Many strategies are given by players to begin with this type of puzzles in strategies pages and videos.
Hand folding de novo S pletsch
Session 7 - Black Belt Folding Postscript
Black Belt Folding LIVE from the Pacific Science Center
Marie-s strategy for hand folding
How to start folding a DeNovo (freestyle) puzzle?
Foldit time-lapse First hour of hand-folding de-novo puzzle 693
Madde hand folding de-novo
see others here Gameplay-Videos