string[] requiredParts = { "hd", "ch" };
foreach (string requiredPart in requiredParts.Where(requiredPart => !fParts.Contains(requiredPart) && !toReturnFigureParts.Contains(SetDefault(requiredPart, genderLook))))
{
toReturnFigureParts.Add(SetDefault(requiredPart, genderLook));
}