How to discipline my toddler...nothing is working?

My 2.5 yr old is deep in his terrible twos and time outs don't do a thing for him. he will constantly get out of the time out chair and even after the time out seems to be a waste of time because 5 minutes later he is back at his terrible ways. His baby sister is 13 days old and i know the recent spike in more bad behavior is due to her being home but thankfully he isn't a biter but he throws toys, shoes, anything he can plus he will hit. I honestly have no clue how to deal with his behavior. I feel horrible disciplining him but i know its the only way he will learn. any parents out there have any suggestions on what to do? bribing him with toys or candy doesn't work.