Maidens hair or a single star twist should conserve a good amount of material. 1/2 or 3/4 inch bar should make a good sized knife.
Both of those patterns use a single bar of straight laminate. Just twist, flatten, and forge.
Definitely do what Reg said and triple your stack istead of doubling. Less heats (leass scale) because it builds the layers alot faster. If you started a billet with ten layers and stacked twice, thirds would give you 90 layers, while halves would only give you 40 layers.