My first thought was no toys, I love oral all on its own, until I read @Craig1234’s comment about the butt plug. This would amp it up a bit for me, but I love the intimacy of him licking, sucking, nibbling me and he does it so well that I wouldn’t want a vibrator distracting me. I try to focus on the feeling rather than just thinking about the orgasm. Before adding any toys, experiment yourself with how you give oral.
Have a read of this for suggestions 
Oral Sex Superbowl
There will be posts for oral sex on a penis but you can always get some tips that are transferable.