Most easy ceilidh dances are the same whichever side of the set you start. I might ask 'couples with 1 man, 1 woman' to put the man on the inside circle if I was calling a 'promenade and move on to the next'.And if they have naturally been lining up man facing woman it makes a Strip easier to have all the men on the same side. At a family ceilidh it's gender free or 'big one twirl the smaller one under your arm'.