i got into making mixtapes VERY recently and the process is pretty straightforward but it confused me a lot. i'm young so the idea of making tapes was fun and all, but i never really understood the logistics of recording music onto a tape, and the guides i found online seemed to assume you knew on some level how tapes work. i still don't really know how tapes work but here's how i stumbled my way into having five mixtapes at the time of writing that i made in like a couple days.

• blank tape: you can get deadstock blank tapes pretty easily online, especially if you go secondhand like on facebook marketplace or mercari and find people offloading blank tapes in bulk for real cheap because no one cares about tapes. or you can get them off amazon like i did but it'll cost more and i regret it since seeing the secondhand prices lol. the kind of tape matters only with regards to how much music you're putting on i guess, i mean there's probably more to it but for most purposes you just have to think about how much you're putting on a tape and swing for 60 minutes or 90 minutes. my tapes are all on the short side but i went with 90 minute tapes because it wasn't much more and it's just nicer to have the option.
• some device to play your music from: you can use like a computer or your phone or something for this but personally i had a lot of issues trying to get it to record from my computer, so i just throw my playlists on my music player/dap (a fiio x1 ii) and then play from there. more details on how to get the music and what to use to connect the details is coming up just keep reading!
• 3.5mm to 3.5mm cord: i somehow had one already laying around that's like several feet long but you can probably get a decent sized one for cheap off amazon or something. you need this to connect your two devices, the source of the music and the tape recorder.
• cassette recorder: my player doubles as a recorder so i don't have to worry about getting a separate device. it's a jensen MCR-75 that i got for $30 off amazon. most cassette nerds would scoff at this and say to get a better quality player but i don't have $150 to throw at a refurbished walkman, and even if i did, it's not like i use tapes often enough to have a reason to throw that kind of money at an old player/recorder. you CAN get a recorder that doesn't also work as a player but like if you wanna save money then something like the jensen i have will do the job.