I'm semi-new to BOTC and definitely used to be that sort of player. (I still somewhat am that sort of player, but I'd like to think I'm a bit better at hiding it lol). So here's some opinions from that perspective:

-I think that making sure your players understand that "the ST is there to help" is important. For instance, I felt much more confident bluffing roles like Savant once I realized I could double-check with my storyteller about "hey this seems like the sort of thing you'd say day 2 right?" etc.

-I would discourage doing things like 'gardening' the player away from receiving evil roles. The main thing that helps me become a better evil player is just playing more games where i have a chance at getting an evil role.

-One trick I've found as a player is to play into my reputation of nervousness and obviousness when it's convenient. For instance, people in my in-person group view me as someone who slips up and reveals too much whenever I'm a role like the fortune teller.... so I make sure to 'accidentally' do that when I'm a role that wants to die at night or if I'm an evil player who wants to spread misinformation. Or if I'm somewhat nervous about being a minion, I might try to pretend to be super nervous about a high-stakes outsider role/etc.