1. practice makes perfect.
2. try a job spell. look into honey jar or candle spells specifically.
3. when you shake your bosses/interviewers hand, try 'the witches handshake' for good measure. as you take his hand, extend your index finger so it touches the persons pulse [wrist] then very strongly think 'hire me'. people say it'll send the idea 'hire me' to the persons brain and subconsciously influence them. i've only done this once [it worked] but without multiple times casting i can't say if it works or it was a fluke, but it wouldn't hurt.