The most effective option to save money on clothing clearly is not to buy any, hence this is what I would recommend.
This strategy can work for several years because most people, myself included, simply have way too much clothing e.g. more than what we can wear at one time. If you have clothes you can not wear at all, get rid of it. Someone else can probably use it.
Now, your average piece of clothing should survive the laundry cycle about 100 times, maybe even 200. If you have 10 shirts, that’s 1000 cycles. Even if you only wear them once before you wash them, that’s three years. This should be sufficient to get well on the way towards financial independence. Some people have even more years worth than that. Consider that many things can happen during this time. You might change your size (usually always a bad idea) or the clothes might go out of fashion. Having less clothes makes it easier to keep up with current trends if you are into that sort of thing. It also means that you can get a new piece more often. This follows from Lanchester’s square law, also applicable to tank warfare.
For the rest of us, I highly recommend sticking with “classical bland”, this means either gray or navy for the guys. For the girls like with most things, it’s more complicated.
But I guess that did not come as a surprise. Oh, I slay me!
To make clothing last longer, you should seriously consider doing laundry less often than that as it wears down the fiber. One way to wash less often is to change clothes appropriate to the task.
You should also learn how to mend holes. I think that pieces that are not directly visible, socks, underwear, anything that goes under the top layer basically should be mended, patches, etc. until it disintegrates. You can pursue the same strategy with towels and bedsheets. For instance, if you only use one towel, it lasts about 4 years. If you only use one (old) bed sheet, it lasts about 3 years before it rips. Quality may vary. Of course this is anecdotal.
Now, suppose after 2-3 years that you actually did run out of, say, pants. What do I do? I would get underwear and socks new, but everything I would get used. Start with freecycle, then move up to thrift stores, and then move on to extreme sales events at outlet stores. Going beyond that constitutes failure, in my not so humble opinion
In my experience, homemade clothing does not really save any money.
Now it may be that you work somewhere were you have to look expensively dressed because someone in corporate thinks it increases your productivity or inspires customer confidence. This often requires paying the part (out of your own pocket, naturally). Again, look for sales, but do not feel too bad about this one: You won’t need those clothes in retirement, therefore they do not delay your retirement by the standard calculation other than making your savings rate smaller. They do not enter on the factor 300 numerator though.