The decision
By now I hope the habit's reasons look less solid than they did. People say yes more often than you predict. They mind less than you think, and they often like being asked. Your reputation is in more danger from hidden problems than from questions. A debt between friends helps hold the friendship together. Doing it yourself is quicker today and slower over the year. Nobody can see that you need anything. And the rule you've been following was made for a household you no longer live in.
You won't really believe any of this until you've tested it, so this chapter is about testing it. Here is the rule I'd suggest.
When you catch the swerve, stop. If help would make a real difference, and your only reasons for not asking are the ones in this book, ask.
The rule leaves room for doing things alone. If you'd honestly prefer to, or the job's a one-off, or the only person available isn't safe to ask, that's a plan, and you can carry on. What the rule removes is the automatic no that comes before you've thought about it.
The wince from chapter 2 will still turn up. Nothing in this chapter prevents it. You make the request with the wince present, in the way you'd make a phone call you were slightly dreading. For many people it fades as their own evidence builds up. I can't promise that it will for you.
Here is how to make a request that's easy to say yes to, and easy to refuse.
Ask one person. A message to a group saying "can anyone help on Saturday?" lets each reader assume that someone else will answer. Pick a person and ask them by name. Choose someone suited to the kind of help you need, and ideally have a second name ready.
Say exactly what you want. Include what, when and for how long. "Could you give me a hand with the move?" is hard to answer, because nobody knows what they'd be agreeing to. "Could you come at ten on Saturday for a couple of hours and help me get boxes into the van?" can be answered on the spot. I don't know of an experiment that tests this directly, so treat it as my advice. It follows from chapter 8. People can't see what you need, so tell them.
Give the reason in a sentence. "My back's bad and I can't lift the big ones." A reason helps the other person judge how much it matters. It also makes the request sound like what it is, one adult asking another for a hand.
Leave room for a no. "If Saturday's no good, just say, and I'll try Tom." This is the answer to the worry from chapter 3 about people who agree because they can't refuse. You give them a way out and you mean it. It also helps you, because a yes from someone who had an exit is one you can believe.
Drop the preamble and the discount. The preamble goes like this. "I'm so sorry to bother you, I know you're really busy, and this is probably a stupid question." It makes the other person reassure you before they've even heard the request. The discount comes at the end. "But honestly don't worry, it doesn't matter, forget I said anything." That talks them out of helping. One "sorry to interrupt" is fine. After that, make the request and stop talking.
Use your voice when you can. In a study by Mahdi Roghanizad and Vanessa Bohns, 45 people each asked ten strangers to fill in a short survey, either face to face or by email, using the same words. Face to face, most of the strangers agreed. By email, hardly anyone did. The askers had expected the two to work about equally well. Those were cold emails to strangers, and a message to a friend is a different thing, so I wouldn't lean on the numbers. For small favours between people who know each other, a text is fine. Just be aware that a written message can be a way of asking so quietly that you can be ignored, and the habit will choose it for that reason. For anything that matters, ring, or ask in person.
Say what it changed. Afterwards, thank them by telling them the result. "Thanks to you I was in bed by ten and not one in the morning." People like to know their help made a difference. Whether being thanked also makes them readier to help next time is less clear, because the research is mixed. Then leave it there. Thanking someone four times and turning up with a large gift are both attempts to close the account, and chapter 6 explained why you don't need to.
Start small. Asking is a skill and you're out of practice, so begin where a no would cost you almost nothing. Borrow a ladder. Ask a colleague to look over an email. Ask for directions when you could have used your phone. Say yes to offers. Keep the record from chapter 3, with your guess before and the result after, because your own results will persuade you more than any study.
Then move up gradually to bigger favours, to people whose opinion matters more to you, and to requests for yourself. Chapter 12 deals with the largest kind.
One more tool. Habits run on cues, so it helps to decide in advance what you'll do when a cue appears. Research on plans of the form "when X happens, I'll do Y" finds that they improve follow-through across many kinds of goal. They work by taking the decision out of the moment, and the moment is where the swerve operates. Here are three you might adapt.
"When I've been stuck for half an hour, I'll message someone before I try again."
"When someone offers to help, I'll say 'yes, thanks' before I've had time to think."
"When a friend asks how I am and waits for the answer, I'll tell them one true thing."
Pick one, write it down, and say it aloud once. It'll feel silly. Do it anyway. My guess is that a plan you've said aloud comes to mind more readily than one you've only thought about.