First thing you do is find out his normal routine everyday, and try to stick to it as best you can. Ask what he likes to do for play time, what he likes for snacks ect... Two year olds can be fun! Use your imagination when playing! Most of the time if they flip out it's due to being bored, or sleepy and hungry. It shouldn't be that bad.
Get him some toys and play with him. Put on a show. Give em some fruits for that EXTRA ENERGY. Mainly sugar cane, straw berries, and watermelon! Ha kidding. Kidding kidding kidding about the watermelon. Too much mess. Do some fun stuff with them on your bucket list! Skydiving! Bungee jumping! Racing at 200mph in a formula one car! Eating scorpions! Live scorpions!! Okay but seriously just do some simple counting by counting how many pills are in the bottle. Make sure you spill em out first! Okay okay but seriously go onto youtube and put on some nursery rhyme videos by Hoopla kidz or kids I forget. Those nursery rhymes will keep the child busy and entertained and even put em to sleep. Just play the whole playlist and youll be good. =D
My nephew, although energetic, wasn't as bad as a two as he is a three. He's easy with me. All he wants to do is play, so I play with him. Same with all the children in my huge family. I think that babysitting is more than giving the kid something to do... You have to be doing it too, and although It can be tiring, the results should be satisfactory.