Set sails for a broad reach:
SKIPPER - The skipper eases the mainsail all the way to the shrouds. When sailing off the wind the general rule of thumb is to ease the main as much as possible without it luffing. You can also look at your leech tell-tales. You want them flying as frequently as possible. If they are stalled, then the main is likely over-trimmed. When the main is eased the boom will want to rise up. The windier it is the more the boom will want to rise. As a result the top of the mainsail will be twisted to leeward and will be ineffective. Counter this by using the boom vang to hold the boom down so that your top batten is approximately parallel to your boom.
CREW - The crew releases the port and starboard jib sheets from the cleats. Then, the crew reaches up to the fore-deck where the jib sheet goes through the block on the self-tacking jib track. The crew pulls the jib sheet out of the deck (towards the sail) so that it is eased the maximum amount. The crew holds the jib sheet about 1.5 to 2 feet away from the clew of the jib. Using his hand, he holds the sheet (and by extension, the sail) forward and as far away from the boat as possible, and down. Holding the jib sheet forward and away from the boat ensures the jib has a full shape, and holding the jib sheet down ensures the top of the jib is trimmed as well as the bottom. If you cannot control the top of the jib, then hold the jib sheet closer to the sail. If the foot of the sail is too flat, hold the jib sheet further away from the sail.
Steer a broad reach course:
SKIPPER - The skipper should be sitting even with the mainsheet block. The boat should be absolutely flat; in breeze the skipper will likely need to sit on the rail to accomplish this. The skipper should be sailing as low of an angle as possible with the jib still full. If she sails too low, the jib will collapse. Sailing high will feel fast, but the higher one sails, the more extra distance is sailed to the next mark.
CREW - The crew should be giving constant feedback to the skipper regarding the wind pressure on the jib. Because the crew is holding the sheet coming off the sail he will have a very good feel for variations in pressure. When it feels like the jib is pulling well and there is good pressure he needs to say this to the skipper. Upon hearing this the skipper should try to sail a bit lower (or a more direct course towards the objective). When it feels like the jib is going light or collapsing, then he needs to say this to the skipper. Upon hearing this the skipper should steer a higher course to regain pressure in the jib.
Steer a wing on wing course:
SKIPPER - The skipper ensures the rudder is in the center of the boat, and uses weight to fine tune the steering. If the skipper needs to head to leeward, she leans to windward to drive the boat down. If the skipper wants to head to windward, she leans to leeward to drive the boat up. To keep the tiller still, it may be useful to "pin" the tiller between your hand and the seat of the boat, or the deck of the boat (depending on where you are sitting).
CREW - Hold the jib forward, out, and down as described above in broad reaching, but this time the jib is opposite the mainsail and not behind it. Keep an eye on the sail and communicate with your skipper about pressure in the jib, as described above. In addition, keep an eye out for the jib luffing, and give feedback to the skipper. Sailing wing on wing successfully means that the boat has to keep the apparent wind within a few degrees of variation, or you lose power in the jib, or jibe the mainsail accidentally. If the crew notices the jib is hanging limp, it may be blanketed by the main. This means the skipper (and crew) need to use weight to steer the boat to windward so the jib can get clean air again. On the other hand, if the crew notices that the jib keeps trying to cross to the leeward side of the boat, then the skipper (and crew) need to shift weight to windward to drive the boat to leeward so that the wind pressure is on the correct side of the jib.
To learn more about jibing down wind with just the jib, visit the page Jibing with Jib located in the Boat-handling section of the site.