Wiffmaster

Hello everyone. I'm totally new to pyro, and am just wondering what you guys reccommend a newbie start off with. I have made the Potassium nitrate/sugar smoke b o m b mix, but have also aquired some ammonium nitrate as well. I would like to include this in my pyrotechnics for miniature explosions/bangs etc (for amateur film work).
Problem is, I can't get it to detonate, and don't really want to go any further without some safety advice (would like to keep all fingers!). I do not have access to tubes/blasting caps etc, just everyday items. What is a suitable safe substitute for the tubes, etc. Also, I was thinking, would a length of string dipped into the melted potassium nitrate/sugar mix act as a crude safety fuse for the ammonium nitrate detonation?
I would like to stay as safe as possible, as i'm just starting out, so sorry for the naive questions.

Many thanks in advance.... :-)

(BTW: am I right in thinking I should type b o m b like that, to stop this site appearing on Google searches for b o m b s.)