Any strategy guide will tell him that. The real trick to Featherwaving mastery is understanding that you can use any kind of feather as an implement. Including magic quills.
So it's entirely possible to use Scriptomancy while Featherwaving. In this way you can write Scrolls of Speed to allow you to more quickly cast Feather's Swiftness, which allows you to more quickly write your Scrolls of Speed, and so you are able to more quickly cast Feather's Swiftness, ect.
Get this combo up high enough and you can instacast pretty much any Featherwavery spell, and from there you become pretty much unstoppable. I mean, maybe something exists that can withstand 5000 Peregrine Strikes a second, but if so I don't want to meet it. Also, if you time it right, you can cast Down of a Phoenix on yourself, essentially making you immortal.
Of course, all this Featherwavery and Scriptomancy is going to use up a lot of mana and paper, respectively, so you'll need to sort that out, and it's not too hard. The first step is acquiring Ambidexterity. The easiest method is using time shenanigans to mess around with your DNA before you were born. Then, while your main hand is doing the Scroll of Speed/Feather's Swiftness combo, you have your other hand writing Scrolls of Mana and casting Winged Messenger sent to yourself with the message kept blank, which will provide the paper.
Unfortunately, while getting the paper is relatively straightforward, receiving the paper is a bit tricky. Whenever a player receives a message from Winged Messenger, they must notarize the Spectral Pigeon's signature pad, which is a bit hard to do when both hands are occupied. That's why you'll need a third signing hand.
The first part of this is easy. Simply acquire a third hand in one of the usual ways; any sort will do other than the one you get from winning a Bardy award or any hand created by Von Neumann-inhibited nanomachines. Where it gets hard is that you'll need to have Ambidexterity II to use it. To get it, you'll have to do the Pickle quest, and just after you've turned in the quest but before you accept your reward, terminate your client. Then log back in as fast as you can, as you need to kill the questgiver, Mr. Wendel, within 10 seconds of you logging out (I recommend hacking your client to stop it from loading all textures and to send a fake authentication signature so you can log back in within the timeframe). He'll drop the Bone of Forming, which you can use in the Dungeon of Concrete Lamps to open a secret door on the third level of the fifth hemidimension to gain access to the Secret Sub-Dungeon of Transforming Mega Spiders. Get to the end of the sub-dungeon and you'll be offered the reward of a Cake of Infinite Wealth, The Tome of Fame, The Cauldron of Hot Bitches, or the blue clay flowerpot. Take the flowerpot, and get out of there as fast as you can, as the secret passage will close shortly after this, and your Bone of Forming will have been eaten by a Transforming Mega Spider in an unskippable cutscene just before you chose your reward.
Once you're out of the dungeon, put some Twilightsoil in your blue clay flowerpot and plant a Bean of Minerva in it (acquiring the Twilightsoil and the Bean of Minerva are both a bit complex, but you should be able to easily find guides for them elsewhere, so I won't waste space describing the processes). Tend the resulting plant, and within 6 months (real-time), you should should have a Bean of Ambidexterity II.
Don't eat this; it's a trick!
What you need to do is wait for a Bean of Ambidexterity V-III to grow (which should be about 3 months after the Bean of Ambidexterity II appeared). Then get it to sprout, plant it in Dusksoil in a red clay pot, and in 12 months you should have your Real Bean of Ambidexterity II. Preserve it in a Stasis Fridge, and repeat until you have 3 of them to make a Three Bean of Ambidexterity II Salad. Eat it and enjoy your new Ambidexterity II.
Of course, there are other ways of gaining Ambidexterity II, but they're a bit more convoluted. Oh, and if you manage to get a Feather Stylus, you can use your signing hand to cast more Featherwavery spells, meaning you don't have to break either of your combos and therefore don't have to sacrifice mana/paper or speed. This means you can summon Mega Ultra Chicken all by yourself in less than a day!