I'm also fairly frugal and a lot of the suggestions, I've been doing for years anyway, because it hasn't really occurred to me to not do them IYSWIM?
So if you read a lot, you use the library instead of buying new books all the time, must cost a fortune. I have a kindle and only 'allow' myself to buy books when they're on offer for 99p. I have quite a few unread books so I'm never going to run out of anything to read and just about everything I want comes round on offer sooner or later.
Likewise putting the washing machine on full most of the time and timing washing so you can dry outside as much as possible (tumble dryers turn clothes into a creased shrunken mess anyway, so I rarely use it, it's not just about the money).
It's not about what you can and cannot afford, more that, for most people, if you spend less you get to work less/retire early or whatever, so it seems a bit mad to be putting yourself in a position where you have to work more to pay for things that you could easily not do, or aren't that bothered about.
Having said that, I'm being a lot more careful about eating out and takeaways because they've both got so expensive, the Chinese takeaway we've been going to for years, even more so, and it's not even as nice as it used to be.
It used to be £10-12 for the two of us, now it's over £20 and the last few times we've had it, I've thought afterwards 'I didn't really enjoy that'.