Slow Play vs Big raise??? How do you Slowplay.. and

[Ivanfrost]

I am trying to learn how to slow play some of my hands so that i will maximize the value of my hands but i am lost how to do it. Usually if i hit big cards i will bet the big cards ie if i hit the nut strait on the flop or turn. But recently i was trying to slow play and this was the situation. I was in late position with 78 and the flop came up 5 9 q rainbow someone bet 50 so i called there were 3 people in the pot. the turn comes a 8 bam i hit it i knew i had it but i wanted to get the most out of this hand the pot was pretty big already so i bet 100 (we were playing in a tournament.) after a bet from the bb. [now this is where is gets jacked up] River turns 5 guy to my left goes all in. I put him on a FH and was right cause i called him. I lost with my strait cause i tryed to slow play.
Need some help here thanks

Ivanfrost