Well the first step is to install traveller control lines. Trying to adjust a traveler with pins can be dangerous as you are restraining the whole weight of the mainsail while you make the adjustment. To tack or jibe without control lines the traveler should be centered so that it can''t slam across the boat. Depending on wind strength, after the tack, in light to moderate winds,the traveller car should be brought to windward of the center of the boat. In heavier air it should be dropped to leeward.