the grid method works but for less experience players may be harder than the 6 black pearls to set up. my advice to anyone trying to get this achievement is to follow these guidelines.
1. work a star flower to the bottom left hand corner so it is above one hexic piece and has one to the left so it is in the corner as far as it can. this is where you will bring your black pearls and put them around this star flower starting by puting your first pearl under the star. this way if a color gets erased from the board your star flower with the pearls will be unaffected.
2. "starwalking" is a method that benefits you the most by giving u control of all peices on the screen. this is done by having two or more starflowers and using them together to manipulate the pieces and travel across the board.
3. using the starwalk with two or more starflowers, move pieces of a same color on a single starflower. you can easily make more starflowers this way. but do not get cocky and start making moves fast because u can easilyu loss 3 to 5 stars by collapsing them together so check your moves thourghly before making them.
4. have atleast 9 starflowers before making a black pearl so that you can continue to make them without losing momentum.
5.you can stack starflowers in a strait vertical line to avoid the risk of collapsing them.
6. keep a few starflowers at the top of the board to have a easier time with the bombs.
7. most of all be patient because it takes a little time to learn how to control all the pieces in a efficent manner and thats what practicing helps with. making efficent moves and not "randumly" mashing the x button will benefit you.
good luck and i hope this helps, if you have questions about this guide then send me PM and i will get back to you with an answer or send a party inv on xbox live.