I have become pretty good at the firework game and here are my tips:
1) practice as much as you can.
2) Having sound on does help me. You can hear a firework being shot up into the sky and you can prepare yourself accordingly.
3) NEVER hold the curser directly over the firework, hold it a little to the side or above it or behind it, this way you can see it when it turns into a star, also this helps explode 2 fireworks that are near eachother.
4) this may be the most important tip: get to know each fireworks personality. The red ones tend to explode faster then the rest ( except for the final blue flakey ones ) and the green ones actually start to fall before turning into a star. The directions say explode them at their peak, but this isnt the case.
5) after you play enough you see some patterns, like in the begenning ov level 5, they shoot 5 or 6 right away, and you cannot get flawless on all of them, so explode 4 of them rifght away and wait for the final 2 to turn into stars.
6) if you see the path of fireworks are going to intersect, and may cause problems when exploding one, try to explode one of them right away, and then get flawless on the second one. Its getter to have a good and flawless then a flawless and an oops.
7) memorize the order of the fireworks on the bottom of the screen. this way you dont have to look down at the firework selector each time a new firework comes.
that takes care of the things you can do in the game, but there are some things you can do with your computer to help.
1) For best results use a wired mouse. Some people would disagree, but its a fact that your time lapse from clicking to getting it on screen is shorter with a corded mouse.
2) use an optical mouse for more precision. ( when I switched to use a corded logitech dual optical mouseman, my score jumped 10K instantly, compared to when i was using my optical wireless mouse )
3) have lots of ram, and a good video card. Believe it or not VMK is a system hog, and will run slower on slower machines
4) try not to have another windows open, especially other VMK windows.
hopefully this helps a little. anything else please let me know. GO TEAM USA!!!