I heard socks work, but they're not as effective or elegant as pop filters. Heard pantyhose can be used too if you have any of those lying around.
I've heard of people making DIY ones with a pair of tights and a metal coathanger. - stretching the material over the coathanger. Personally, I don't use one and just position the mic to one side and slightly below my mouth and I never get any pops.
It's not so much the distance - you can have it really close - just make sure it's to one side (about 45° angle) so that the exhaled air goes past it but not onto it.
I put the microphone close to my mouth but a little bit to the right and have no problems, I also paid £30 for a pop filter which I don't use lol