I hand wash 'the pieces' in cool water. Then rinse in cool water. I use
UNICORN FIBER WASH & RINSE,
but Eucalan is good, too.
squeeze out the excess water (no twisting), then pat/press again between thirsty bath towels (with no fabric softener).
Then lay pieces out on blocking board, pat into shape, pin sides into shape, if necessary. Sometimes I also use long blocking wires on the long straight edges, too.
All blocking BEFORE seaming.