Here are some suggestions
1) Don't bother with replacement things (patches, gum) they absolve responsibility.
2) Having given up, if you smoke a cigarette, think - I've had a cigarette but I am still giving up and throw away the pack if you have any. Don't think - I clearly can't give up, I am smoking again.
3) In the lead up to giving up, make smoking unpleasant. You can only smoke in the yard for example. Remove any social aspect to smoking, smoke by yourself.
4) Avoid smoking situations for a bit. Avoid smoking buddies and situations where smoking is the norm. Just duck out of them for a little while - arrange to meet smoking buddies in a situation where smoking is not possible or difficult. And if you do smoke remember point 2.
Good luck.