Lots of retail advice here

The last selection really did help me to improve my life without really trying, so I'm back to not making an effort

41 Buy a plant. Think you’ll kill it? Buy a fake one.
I agree that plants are good things that improve your life.  However, surely a fake plant is just going to be a constant reminder of your inability to look after things - and you'll have to dust it as well, which is super annoying.  Instead, can I recommend you buy one of the Tradescantia family?  We've got one which we've killed several times (and I mean properly killed - no leaves left) because we put it somewhere where we forgot to water it (not a brilliant strategy).  But every time it's come back to life with a bit of water, which makes you feel like a proper gardener rather than someone who just mindlessly slaughters things.

42 Don’t have Twitter on your phone.
I actually agree with this - I have Facebook on my phone, but not Twitter because it just feels like I don't need it there.  So this advice really isn't going to involve any effort on my part, but feel free to follow in my wise footsteps!

43 If you find an item of clothing you love and are certain you will wear for ever, buy three.
And they will act as a constant reminder to you as to exactly how wrong you were when you were certain you'd wear it for ever.

44 Try taking a cold shower (30 seconds to two minutes) before your hot one. It’s good for your health – both physical and mental.
Hmmm - I'm almost tempted by this one.  Although I love a hot shower, so I'm not entirely sure a cold one is going to improve my mental health - but I guess maybe I'll love a hot shower even more after a cold one.  However, I'm just out of the shower, so I'm not about to try this now.  Maybe tomorrow morning (he says, knowing perfectly well he'll forget)

45 Text to say thank you.
Yup, I agree with this.  As well as being the polite thing to do, it lets people know you are thinking of them and that you got home safely (if this is relevant).

46 Read a poem every day. Keep a compendium, such as A Poem for Every Day of the Year, by your bed.
The only slight problem with this is that some poems are, shall we say, utterly shit.  How is that going to make my life better?  If there was a book entitled A Good Poem For Every Day of the Year, then maybe I'd be in (but probably not).  Poetry is very Guardian - they always like to shoehorn it in there somewhere.

47 Take out your headphones when walking – listen to the world.
Hmmm - not sure about this one.  Going for a walk feels like the main thing here and we've covered walks before (but without your phone, obviously!).  And yeah, take your headphones out if there's something to listen to - but sometimes it's nice to have your own soundtrack to your walk.  Definitely go for a walk, but feel free to take your phone and your headphones.

48 Buy secondhand.
I guess this all depends on what you're buying.  I'm happy to buy stuff secondhand, but most of the stuff I buy doesn't really lend itself to the secondhand market.  I guess I look at books in charity shops, but they are always so disorganised that it's an annoying struggle - except for the Oxfam bookshop which is marvellously organised by genre and alphabetical order.  We do sell or give away a lot of stuff on reuse sites though - we're good people, honest!

49 Buy in person!
I don't know if this advice is slanted towards increased personal contact or supporting independent retailers, but either way I guess it helps improve your life and theirs.  I'm trying not to use Amazon as much as I used to, but I must admit I fall victim to the convenience and/or the massive price difference from time to time.

50 Learn how to floss properly.

Ah, flossing - so 2018.  I know, I know - not that kind of flossing.  Our dentist has actually given up telling us to floss and moved on to nagging us to use interdental brushes (and yes, I had to check whether it was inter or intra) - part of me is suspicious that they look more impressive so they're easier for him to flog, but I do have to admit they work.  When I remember to use them - unfortunately just keeping one in the toothbrush pot doesn't seem to have any effect.

Let's go for the retail advice here and buy secondhand plants in person to make our lives better - and then text to say thank you.  Do not, however, buy three items of clothing.

31-40 : Why the obsession with leaving your phone behind?
51-60 : A genuinely good suggestion