Disclaimer: I've been asked to state that the use of a boggle solver can result in a ban from the developers. Please use at your own risk
If you're having trouble with this naturally there are two approaches.
1. Use a boggle solver, like below. Use large words and try and achieve 50% or more.http://wineverygame.com/boggle/helper.pl
2. Play in another language with few players in the lobby. Arabic almost always has barely anyone playing. Even if you don't know Arabic, you can still guess words. I've placed 1st place a few times actually.