Well, the magic word will surely depend on the situation.
Quite often the correct answer will be please.
But sometimes please just doesn't do it. A stronger more magic word is required.
Back in 1992 I spent some months in Minnesota, and I had the privilege of being allowed to help out at auctions held by the then oldest auctioneer company in Minnesota: "Fred Radde and sons, auctioneers and realtors"
Fred the main auctioneer knew the magic word for Minnesotan auctions was "Fish house". If an old crappy sofa or chair was unsaleable, calling it a fish house chair would instantly spark the interest in the crowd and someone would buy it for their fish house for the coming winter season of ice fishing (a great sport by the way). Fred's next comment would usually be in line with: "buy it now and leave it on the ice, in the spring it will be gone".
He really knew how to make a good atmosphere and that stimulated people to buy, and all in all it contributed to a nice event with lots of laughter and good deals.
Now in my case "fish house" wont do it. "Please" works sometimes, but "HORSE" works every single time.
If I need to start a new project:
"Honey, I'll go mill some wood to make some saw dust to spread in the stable for the horses to sleep in".
Such an approach will be greatly appreciated, in contrast to e.g.:
"Honey, I'll start building a new workbench"
There are a number of situations where you can use the magic word, tool purchases, classes etc. the imagination is the limit.
In reality you want to say: While I don't really need this tool, I am sure it would impress someone reading my blog.
Chances are that my request will be frowned upon and quickly be discarded as not essential for the household.
If I on the other hand say something like this:
"If I buy this tool, I could make a really nice cupboard for the saddle room, so you can easily organize the tendon boots for the horses."
I am sure you get the idea.
So I am thinking that a lot of the advice offered for aspiring woodworkers start in the wrong place such as:
Advice for a beginners tool kit.
What planes to buy and when.
The first saw you should get.
And so on....
A much better place to start would be by finding the magic word. The very word that will allow you to invest time and money in your hobby and being thanked for it. Now that is something that isn't described in a lot of "how to posts" for people wanting to get into woodworking.
We are not talking complicated psychology here, a good look at your wife's hobbies will most likely give an idea of what the magic word could be, Here are a couple of suggestions that might work, but remember like in Harry Potter, there is always the risk of a magic spell backfiring on you, so be careful!
Gardening (this one is dangerous because you could end up using a shovel all day long instead).
Bespoke baking supplies.
Doll house (this one might make it difficult to justify getting a portable saw mill)
Finally, you shouldn't feel bad about using a magic word, because I am fairly certain that we are under their spell most of the time anyway.