I don't want to be cheesy but honestly you should be yourself
If you get someone by doing stuff you wouldn't normally do, then they are expecting a different version of you
You should try to find authentic connections
OnlyFans feels kinda meh in that respect (to me at least)
if you want to know specifically about the smileys and emojis and stuff honestly I think that depends, I used to use XD until a girl told me it was cringey and eventually I noticed it was. But I've also talked to other guys and girls that still use XD, same for emojis, some people use them a lot and some don't at all.
If you want to know what works on the girl you're talking to, see if she's left hints, if her comments or posts always have emojis, or certain ones, none at all, etc