Sparklers create a grand exit -- the next best thing to fireworks! Make it easy for guests by providing buckets of sparklers. Line walkway with lit votive candles so guests can easily light their sparklers.
Birthday Party via Brit + Message Wall: This year, skip the birthday cards. Tape black butcher paper to the wall and leave out some metallic gel pens (remember those?) for guests to leave you some epic birthday messages. (via Hostess with the Mostess)
Bonfire Birthday Party Ideas for Food, Decorations and Fun
Little Details Sparklers! You can generally buy them cheap from anywhere around October/November time, but I know that Asda have, from the October, a pack of 5 normal sparklers for just Make sure that all of your guests have at least one!