To make an impact smoke bomb you should first create a mixture that releases smoke while burning (such as sugar and KNO3), and surround it with an outter shell of easily ignited material and strikers. Some examples are:
Match heads and strikers, with the match heads between the strikers and the smoke mixture.
Caps and blackpowder around the smoke mixture and masking tape on the outside.
Flash Paper and flash powder, flash powder being between the paper and the mixture.