On my Catalina 28, I head into the wind while under sail (no motor), and make sure I have the slack out of the topping lift so the boom won't fall. Always double check it.
With the boat into the wind I release the main halyard and let the sail drop. On my boat, the halyard runs to the cockpit, so I do this while standing at the companionway. I just let the main drop wherever it wants.
As soon as it falls as far as it can on it's own, I immediately go forward to the mast and tug it down the rest of the way. DONE.
All that's left at this point is to go to the aft end of the boom and begin flaking the sail. I have four, 4ft lengths of line that I use for sail ties. I have them draped on my neck so I can devote two hands to the flaking and easily grab the next securing line when I need it.
The only other technique I employ is to use the topping lift to lower the boom a couple feet so I can get to it easier while I flake the sail.
If your halyard doesn't go to the cockpit, that's no big deal. Everything I've described above still applies, except you'll release the halyard at the mast.
Probably the key thing is to do it smoothly and QUICKLY. On a windy day, you can expect your boat to turn its beam to the wind, and that can cause the main to flop around, which can be unnerving. Don't let it bother you. Get yourself to the aft end of the boom and get to work.
I'm right handed, and when I flake the sail I find it's easier for me if I do my best to quickly throw the sail over to the starboard side of the boom. Makes the flaking process more orderly for me.
Remember, flaking depends mainly on being at the far aft end of the boom and pulling the sail toward you. Hard. Pull it toward you with one hand and fold a section of it over with the other. Hold the first fold in place as best you can, while you pull back to create the next fold. after 3 or 4 folds, secure it with a line...makes a lot of sense to have the securing lines VERY handy.
The part that requires the most practice is holding the sail in place while you get it secured with the line. While keeping it in place, I quickly grab a 4ft. line from around my neck and drape it over the sail and boom. The trick is to not let the folds you've put in fall while you grab the two ends of the draped line and wrap them around. Once you have them wrapped around, you can pull taut on the two ends and that part of the sail is SECURE, and as good as done. Doesn't matter at all how much the remaining part of the sail flops around, because this part is SECURE. Now, all you have to do is tie it off with a loose square knot or a bow (yeah, I use a bow for this...why not?). Repeat three times and you'll have a fully secured sail.
Once fully furled, adjust your topping lift and tighten down the mainsheet to keep the boom from flopping around. I like to further secure the boom by using an old piece of line to secure the end of the boom to the backstay.
Each of the steps requires practice. And confidence. Secure in the knowledge that you're doing it right will give you the confidence. Practice will allow you to complete each step quickly with the goal in mind. You'll soon be oblivious to the lowered, flapping and unruly sail once you've confidently mastered flaking.