Sharing this in case it's of interest. Discovered as several mummy bloggers tweeted a link to it.
It's called How to Live For Free and it's free to download on Amazon but I think only for a limited time. I've dipped a toe in; it's got tips on (for e.g.) how to get a free massage, tips for hitchhiking, getting free products from brands, becoming a mystery shopper etc. Liking so far.
www.amazon.co.uk/How-Live-For-Free-Definitive-ebook/dp/B00Q38CDKI/ref=pd_rhf_ee_p_img_1