Surely, you can use brackets, like that))), The more the better, but you should limit your sarcsam just as well. Also you can add particle ну, like that, Ну конечно)), ну ты молодоец)) ну ты даешь)) It makes your sarcasm even more prominent. IF you exaggerate something it also looks like sarcasm. Too much sarcasm sounds insulting. Beware))