I don't have much experience with this, and I doubt it'll work for me, still I must try. So, I know ducktape is a bad idea, and I don't want to invest a fortune in something that I might try once and regret the purchase. Sports stuff makes me already nervous on a daily basis, some days almost constantly, anything that restricts my breathing in any way makes me nervous... So I thought perhaps I could give really tight t-shirts a try, from the kid's section, just cutting the sleeves and trying to fit in there, see how it feels. They are quite cheap. Hopefully I'll give my shoulders a well deserved rest, the muscles are always tense, and they hurt, clearly from having to endure the weight, and also the pressure of the straps. I'm trying to go top commando, but spring is almost here and obviously to attract attention is the last thing that would aid to blend in (besides it's uncomfortable too), so I'm about to try kid's t-shirts. Some days the anxiety and discomfort is just too much, I need to find a solution that works until I manage to get surgery (by the way, I can't just lose more weight, I'm getting closer to the line between sick and healthy). Have you experimented with tight kid's t-shirts? Anything against it? (crushed ribs, whatever...)
Thing is right t-shirts would compress your stomach too which isn't ideal and would probably cause bloating and be really uncomfortable. Also you'd probably find it difficult to get over your shoulders because the material isn't made to stretch like that, you'll probably find that it tears if you're forcing yourself into it. I mean any binder is going to restrict breathing, its compression on your chest no matter how decent your binding method is. I've heard of people using old swimming costume and cutting the bottom off and sewing the top half up into a sports bra type shape that compresses? I know that's still sports stuff but its the safest method of binding that I can think of that doesn't involve a big purchase.
I agree with Aberrance, I think cotton isn't the ideal fabric to bind because it doesn't stretch. If it's too tight and worn for too long you could possibly bruise your ribs and to be honest I think it would be even more uncomfortable than a tight sports bra. There are cheap binders on ebay for like 10 euros (shipping included) that might work for you, depending on your chest size.
I haven't tried tshirts. I don't think it would work very well. Due to money for a while I used cheap asian binders that are like $5 on amazon. Not the best, but its something. Though I don't suggest it for guys with large chests.
I don't have experience with small shirts honestly, so I wouldn't know personally. If you're going to get a binder online, aim for GC2B or Underworks (since they're general the most cost affordable). Just be sure to check the size charts first, and stay clear of the $5-$10 ones you see on ebay. They're cheaply made and you can do a number on your ribs and back with them.
I wouldn't recommend the cheap ones on ebay. They're not really gonna bind more safely than a cotton t. I suspect a cotton t that would be tight enough to really bind your chest would probably restrict your breathing in an uncomfortable way. My recommendation is a proper binder. Just look for one that's very breathable, and possibly a velcro binder so you can adjust how tight it is and take it off quickly and easily if it's making you uncomfortable. I own this one (here) and find it binds well but still feels very easy to breathe. My chest is pretty small so I don't have to wear it too tight for it to bind effectively, but if your chest is small and/or you don't need your chest 100% flat, you could also wear it slightly looser than a standard binder, which makes it even more breathable.
Yup, stay clear of cheap binders. I have good experiences with a cut-up pair of tights, but I don't EXACTLY know if it's 100% safe. You can google it!
If you can't stand feeling like your chest is being squeezed, GC2B is really your best bet. If you order through Amazon, you can also return it for a refund, unlike GC2B's own stringent return policy. I've tried a -lot- of cheap binding methods, and let me tell you I wish I could revoke all the money I've put towards eBay $7 binders and tight sports bras and fabrics to bind with, and go straight for GC2B binders. It's worth $23 more to not feel like you might die in this garment. Every time you think you might want to buy a cheap binder, from AFK or whatever, stop. Put that money aside. Don't get the awful binder. Within 3-ish times of wanting to get an awful binder, you will then have a good binder that will actually give you a chance of liking binding instead of just suffering. And if you still don't like binding, there are a lot of people who need donations or discounted binders.