Hearthpwn

Watch my 6th turn

https://hsreplay.net/replay/8MsA8ktF8MLTvzdkCwbR4M

I play Wild Pyromancer, Power Word: Shield, Holy Smite and Cat Trick triggers only after Holy Smite

What??? Why?? 

There was no room for the Cat Trick to pop when you played the PW: Shield. If there isn't room for the minion to be summoned, the secret won't trigger. Once the board was wiped down to just the Dire Mole, the Cat Trick can be popped.

Their board was full so cat trick couldn't go off

2 things. 

1) Serves you right for playing razakus.

2) Opponent had 7 minions on the board when you played PW:S.  Since there were 7 minions, Cat Trick could not activate at that time.  Then Wild Pyromancer's effect activated, clearing board space, then you Holy Smited.  Since board space was available at that point, the secret triggered.

In general, secrets will never waste themselves by triggering at a time when there would be no effect. The most straightforward example of this is Competitive Spirit, which will never trigger when you have no minions. So while I commend your idea to play around secrets in that way, you can stop trying.