I make hay by hand each year
The grass is cut with a push along strimmer and I leave it to dry in the sun, its usually ready by the next day's afternoon. Its raked into rows and then the rows are raked into a big pile of hay.
I use a feed bin (or black rubbish bin) and lay the bailer twin inside it in a X shape with the bits hanging out the end. The hay is then stuffed in until pretty solid, the string is tied and the bale lifted out, its hard work but the bales do stay together.
I used to use a cardboard box but the hay can be compacted much more in a solid feed bin.
I have to admit that this will probly be the last year we have made hay, due to us needing the grass for grazing and being supplied with big bale hay for free. So not much point in making it any more