Source: catamaranguru.com

CAUTION: This is not politically correct seamanship!  

Most sailors mistakenly think that there is only one way to raise and lower sails. The standard procedure we have all learned is this: the helmsman uses the diesel engine to hold the bow into the wind while the mainsail is hoisted by another crew member. 

With lazy jacks on the main this can be a challenge because if the boat is not pointing perfectly into the wind, then the leech of the sail and the battens hook up with the lazy jacks. I have watched many a crew getting quite testy with each other as they try to co-ordinate the maneuver, and truth is, it can be quite frustrating.

Once the main sail is up at last, then the jib is deployed as the helmsman bears away, filling the sails with wind, and finally, the engine is then switched off.

TIP: Consider the auto pilot a third crew member: a good idea is to engage the autopilot while slowly motoring forward and then adjust the heading until you are heading directly into the wind. Now you do not have to worry about the helmsman keeping the head to wind and he can assist the crew with the hoisting of the main sail.

Now, there is no rule that says the main has to go up first. You can also leave the anchorage and deploy the Jib first. The good thing about deploying the jib first, is that one does not have to be heading into wind and there are no lazy jacks to snag the leech of the sail.
Once the jib is deployed, head up so that you are close reaching with the jib only (engage the auto pilot if you'd like).

Once you have settled down and the boat has way on, sailing nicely, the next thing to do is release the main sheet and push the boom out to leeward. Now, while sailing, you can hoist the main. Because the boom is out to leeward, the main sail will be completely luffed and there will be no pressure on the sail, and so you will have the same effect as being head to wind.

You will be able to hoist the main in a controlled manner while underway and once it is up, all you need to do is trim in the main sheet and you will be sailing with both sails up and the engine would have long since been switched off! How neat is that?

Wait, it gets better!
If you think about this in reverse, it is the best way to put a reef into the main sail: while under full sail, head up to a close reach, ease the main sheet until the main sail luffs, release the man halyard until the next reef points are at boom level, make them fast and then tension the halyard, trim the mainsail in and you are now sailing with a reef in the sail. You never missed a beat and did the entire operation while sailing – no engine required. This is after all a sailing vessel!

Another easy way to hoist the main without using the engine and this is to heave-to.
The sequence to follow is to leave the anchorage under power and as soon as it is prudent, deploy the jib, turn the engine off and sail out to clear water where you have space to maneuver. Next comes the heave-to. The way to do this is to tack the yacht without touching anything (do not touch the jib sheets). The boat will tack and the jib will be back winded because you did not release the sheet so the wind will now be pushing the bow to leeward.
Now turn the helm hard over to turn the boat to windward as if you are trying to get back in the original tack. What will happen is: the backwinded jib will be cancelled out by the rudder, which is exerting force in the opposite direction.
The result is that the boat will stop and stabilize and it will feel as if you were parked with the bow at about 45 degrees to the wind. Make sure you lash the helm over so that you remain hove-to. You will then be able to release the mainsheet, push the boom out until the main sail is luffed and hoist the main.
You can also hove-to if you want to put a reef into the main sail or drop it completely.

If you practice hoisting and lowering the main while under sail as well as using these methods to reef the main sail, you will very quickly find that your sailing ability and expertise will dramatically improve. It is also good to be comfortable using all the different methods from a safety point of view - you never know when you will need to use the sails because the engine will not start.

TIP: A word of advice that I always follow – before you start dropping sails start your engine to make sure that you have propulsion once the sails have been stowed. Once all the sails are down is not the time to discover that your engine will not start!