cut it thicker, allow your self enough room to put it up. i have some what thick hair though but i am also verry carefull when it comes to shaving it especially if im bicking it. it is always easy to accidentally cut too much off. but the more i bleach my hair it seems alittle more thin maybe just me getting parinoid idk. but how i did mine was i combed it parting the sides one at a time and then cut the sides off. try leaving all of the top hair. if it doesnt look right to you you can cut more off but just really thin peices at a time. its better to go to thick then too thin.

my hair is pretty thin too all i use it freeze it hair spray the mega freeze one, it hold really well for my hair. i usually do mine in a death hawk, and fan it sometimes, and just use the same stuff. i get it at wal-mart it comes in a gold can. but you have to watch it because if you use to much or spray it too close it will turn white and flakey. it works the best for me though, hold up in humidity very well.

To avoid gaps, I usually put wella shockwaves styling steel gel in (really strong gel, that goes 'crispy' instead of 'waxy' like got2b glued styling glue does) and then comb it as i blow dry it, so its thicker. Then I use a minimal amount of the got2b glued styling glue to shape it into a fan, and freeze it with got2b glued spray and a hairdrier.