Amateur tip: DIY reno work is the ultimate personal finance hack.
The only labour you'll do in your life in which you'll get to receive most of the value is working on your own home. Because of the capital gains exemption from the sale of a primary residence, it's the only time in your life where you can do valuable work and not pay taxes.
Many skilled tradespeople are going to be paying 35-40% of their wages in taxes too. This means if you hire them, you pay their income taxes, unless they have mispriced their work entirely, in which case either you or they are getting ripped off. Another way of looking at this is you can do the work they do, be 35-40% slower at it, and still break even. If you happen to get better than that, that's free money for you.
There are side benefits to being a DIYer.
You don't worry about your house as much – things aren't as intimidating once you've taken them apart and put them back together a few times.
You can help friends and family with their projects – having a store of social capital is as important as a stash of money, and a lot more gratifying to spend.
You will never be entangled in litigation, get ripped off, or tear your hair out trying to find someone to work with.
You get exactly what you want out of a house, and you can afford better appliances and finishes. Cook your lentils on a Miele range with quartz countertops you installed yourself.
You have a wider selection of houses available to you, and market swings are cushioned by your thriftiness
There is a perception that DIY isn't as good as the pros, but having worked in the construction industry I can attest that some of the best work is done by homeowners, and some of the worst done by contractors. Yet anyone can choose to do quality work: just be that person. There are no real secrets in light construction.
There is another perception that it isn't worth your effort to spend time learning new things, because you already have a job and that's enough. Don't be that person – your time isn't actually all the valuable, you are not the CEO of a Fortune 500 company. If you are the kind of person who has a mortgage you are likely the kind of person who could benefit from building their own deck.
Buy low, swing hammer, sell high, pay no taxes. What do you think?
Edit: super interesting replies, thanks for all this. There are a lot of personal thresholds at play here, plainly. There are even some $370k CEOs! But I made a mistake in my original post, as pointed out in this helpful comment – the tax thing is more impactful because the average person will pay a contractor with after-tax dollars, meaning that work is heavily taxed on the money going in and going out. Ouch.