I can't remember the hankie code color for spanking (and folks aren't as much into the gay semiotics of hankie codes, key chains, and red ties anymore). So to indicate you're a spanking bottom, I would suggest walking around bent over with a guy spanking your bare ass. That should send a signal, however subtle, that you're a spank pig.
What did you do wrong to deserve a spanking? It's more so what did you do right! Such as admit you want it then go out and get it. Sure, maybe some role play can be involved, like that you were late on the rent so your landlord spanked you, or you were late on your homework so your professor spanked you, or you were late on being spanked, so some guy spanked you. That's about it.
Well, really, you don't even need role playing. You can just be yourself and dig the feeling, whether it's thuddy spanking or sharper spanking or a spank followed by a massage followed by a spank followed by a jack followed by a fuck followed by a tofu sandwich. And a tofu sandwich is not a sex move. It's literally a tofu sandwich. You might be hungry after. Spanking and getting spanked takes a lot of energy and builds it up too. The endorphin rush (if built up right) can be astounding. That's why it's important for the top to make sure not to injure you because you might not be able to feel pain the same in that heightened state. No spanking the coccyx! Tee hee, I said coccyx.
Spanking can also be fun over clothes. And it can be gentle or hard. Technically, it can involve implements but there's just something to be said for a bare hand on your bare ass. Maybe a gloved hand if you want it rougher.
As kinks go, you'll likely be able to find a spanking buddy, or ten, if you put it out there. And if you want to spank folks, put in some time as the bottom too. That will make you a better top. And guess this post makes me a fetish cheerleader. Go team!
Now what are you and your buddy going to pick for a safe word? How about ouch? No that would be too confusing because you might need to say ouch but not have the guy stop. So just go with the basic: rutabaga. Nobody ever has any reason to say the word rutabaga besides to get someone to slow down or stop spanking them. Everyone knows that. Especially the Rutabaga Council of America. Bunch of anti-spanking creeps.
Now watch a footballer get spanked and fucked. It's what the internet is for, unless that exact thing is going on outside your window right now. In which case, join in!